<PAGE>   1
 
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                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                           -------------------------
 
                                AMENDMENT NO. 1
                                       TO
                                   FORM 10-K
 
[X]           ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE
                        SECURITIES EXCHANGE ACT OF 1934
 
                                       OR
 
[ ]           TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(D) OF
                      THE SECURITIES EXCHANGE ACT OF 1934
 
                  FOR THE FISCAL YEAR ENDED DECEMBER 31, 1998
                         COMMISSION FILE NUMBER 0-6136
 
                             CORUS BANKSHARES, INC.
             (Exact name of registrant as specified in its charter)
 
                                   MINNESOTA
                    (State of incorporation of organization)
 
                    3959 N. LINCOLN AVE., CHICAGO, ILLINOIS
                    (Address of principal executive offices)
                                   41-0823592
                      (I.R.S. Employer Identification No.)
 
                                   60613-2431
                                   (Zip Code)
 
                                 (773) 832-3088
                        (Registrant's telephone number)
 
          SECURITIES REGISTERED PURSUANT TO SECTION 12(B) OF THE ACT:
 
                              TITLE OF EACH CLASS
                    Common stock, par value $0.05 per share
                      NAME OF EXCHANGE ON WHICH REGISTERED
                                     NASDAQ
 
     Registrant (1) has filed all reports required to be filed by Section 13 or
15(d) of the Securities Exchange Act of 1934 during the preceding 12 months and
(2) has been subject to such filing requirements for the past 90 days.
Yes [X]  No [ ]
 
     Indicate by check mark if disclosure of delinquent filers pursuant to Item
405 of Regulation S-K is not contained herein, and will not be contained, to the
best of registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K. [ ]
 
                      DOCUMENTS INCORPORATED BY REFERENCE
 
     Parts I and II of this Form 10-K incorporate by reference certain
information from the Registrant's 1998 Annual Report to Shareholders. Part III
of this Form 10-K incorporates by reference certain information from the
Registrant's definitive Proxy Statement dated March 17, 1999, for its Annual
Meeting of Shareholders to be held on April 28, 1999.
 
     On February 28, 1999, the Registrant had 14,519,890 common shares
outstanding. Of these, 7,284,555 common shares having an aggregate market value
(based on the closing price for these shares as reported in a summary of
national market issues in The Wall Street Journal for stocks listed on NASDAQ on
February 28, 1999) of approximately $239.5 million, were owned by shareholders
other than directors and executive officers of the Registrant and any other
person known by the Registrant as of the date hereof to beneficially own five
percent or more of Registrant's common shares.
--------------------------------------------------------------------------------
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<PAGE>   2
 
                                    PART I.
 
ITEM 1. BUSINESS
 
     Corus Bankshares, Inc., incorporated in Minnesota in 1958, is a bank
holding company registered under the Bank Holding Company Act of 1956. Corus
provides consumer and corporate banking products and services through its
wholly-owned banking subsidiary, Corus Bank, N.A.
 
     The bank has eleven branches in the Chicago metropolitan area and offers
general banking services such as checking, savings, money market and time
deposit accounts; commercial, mortgage, home equity, student and personal loans;
trust and investment management services; safe deposit boxes and a variety of
additional services. The bank also provides clearing, depository and credit
services to more than 550 currency exchanges in the Chicago area and an
additional 20 in Milwaukee, Wisconsin.
 
     Corus owns an operations subsidiary, Bancorp Operations Company, that
comprises an insignificant portion of Corus' total assets and net income.
Bancorp Operations Company provides item processing, bookkeeping and other
ancillary bank support services to Corus' bank subsidiary.
 
COMPETITION
 
     All of Corus' principal business activities are highly competitive. Corus
competes actively with other financial services providers offering a wide array
of financial products and services. The competitors include other banks, savings
and loan associations, credit unions, brokerage firms, finance companies,
insurance companies, mutual funds and mortgage bankers. Competition is generally
in the form of interest rates and points charged on loans, interest rates paid
on deposits, service charges, banking hours, fiduciary services and other
service-related products.
 
EMPLOYEES
 
     At December 31, 1998, Corus employed a total of 674 full-time equivalent
persons, consisting of 138 executives, management and supervisory personnel and
536 clerical and secretarial employees.
 
SUPERVISION AND REGULATION
 
General
 
     Corus is a bank holding company within the meaning of the Bank Holding
Company Act of 1956, as amended (the Act), and is registered as such with the
Board of Governors of the Federal Reserve System (the Federal Reserve Board).
The Act requires every bank holding company to obtain the prior approval of the
Federal Reserve Board before acquiring, merging with or consolidating into
another bank holding company, acquiring substantially all the assets of any
bank, or acquiring direct or indirect ownership or control of 5% or more of the
voting shares of any bank or bank holding company.
 
                                        1
<PAGE>   3
 
     The Act also prohibits a bank holding company, with certain exceptions,
from acquiring direct or indirect ownership or control of 5% or more of the
voting shares of any company which is not a bank and from engaging in any
business other than that of banking, managing and controlling banks or
furnishing services to banks and their subsidiaries. However, Corus may engage
in and own shares of companies engaged in certain businesses determined by the
Federal Reserve Board to be closely related to banking or managing or
controlling banks.
 
     The Illinois Bank Holding Company Act of 1957 (the Illinois Act), as
amended, permits Corus to acquire banks located anywhere in Illinois. Other
amendments of the Illinois Act authorize combinations between banks and bank
holding companies located in Illinois and banks and bank holding companies
located in another state if that other state has passed legislation granting
similar privileges to Illinois banks and bank holding companies. Effective
December 1, 1990, holding companies from any state were permitted to acquire
Illinois banks and bank holding companies if the other state allows Illinois
bank holding companies the same privilege. In June 1993, the Illinois Act was
amended to eliminate all branch restrictions. Accordingly, banks located in
Illinois are permitted to establish branches anywhere in the state.
 
     Corus' subsidiary bank is a national bank and, as such, is supervised,
examined and regulated by the Office of the Comptroller of the Currency under
the National Bank Act. Since a national bank is also a member of the Federal
Reserve System and its deposits are insured by the Federal Deposit Insurance
Corporation (FDIC), the subsidiary bank is also subject to the applicable
provisions of the Federal Reserve Act, the Federal Deposit Insurance Act, and,
in certain respects, to state laws applicable to financial institutions.
 
     The subsidiary bank is subject to FDIC deposit insurance assessments. Under
the FDIC's risk-based assessment system, the assessment rate is based on
classification of a depository institution in one of nine risk assessment
categories. Such classification is based upon the institution's capital level
and upon certain supervisory evaluations of the institution by its primary
regulator. The subsidiary bank's FDIC deposit insurance cost for 1999 will be
approximately .01% of deposits.
 
     The Federal Deposit Insurance Corporation Improvement Act of 1991 (FDICIA)
initiated new intense regulation for the financial services industry. FDICIA
made significant changes in the legal environment for insured banks, including
reductions in insurance coverage for certain types of deposits, increases in
consumer-oriented requirements, and substantial revisions in the supervision,
examination and audit processes. FDICIA also required new reporting by banks and
mandated adoption of new regulations concerning capital, liquidity, internal
controls, safety and soundness and prompt corrective action.
 
Capital Adequacy
 
     The Federal Reserve Board established risk-based capital guidelines that
require bank holding companies to maintain minimum ratios. The main objective of
the risk-based capital requirements is to provide a fair and consistent
framework for comparing capital positions of all banking institutions. Under
these guidelines, capital consists of two components, core capital elements
(Tier 1 capital) and supplementary capital elements
 
                                        2
<PAGE>   4
 
(Tier 2 capital). Assets and off-balance-sheet items are assigned broad risk
categories. The aggregate dollar value of each category is multiplied by a risk
weight associated with this category.
 
     In 1992, the FDIC adopted new regulations that defined five capital
categories for purposes of implementing the requirements under FDICIA. The five
capital categories, which range from "well-capitalized" to "critically
under-capitalized", are based on the level of risk-based capital measures. The
minimum risk-based capital ratios for Tier 1 capital to risk-weighted assets and
total risk-based capital to risk-weighted assets to be classified as
well-capitalized are 6.0% and 10.0%, respectively. At December 31, 1998, Corus'
Tier 1 capital and total risk-based capital ratios were 15.0% and 18.1%,
respectively.
 
     In addition, bank regulatory agencies established a leverage ratio to
supplement the risk-based capital guidelines. The leverage ratio is intended to
ensure that adequate capital is maintained against risks other than credit risk.
A minimum required ratio of Tier 1 capital to total assets of 3.0% is required
for the highest quality bank holding companies that are not anticipating or
experiencing significant growth. All other banking institutions must maintain a
leverage ratio of 4.0% to 5.0% depending upon an institution's particular risk
profile. At December 31, 1998, Corus' leverage ratio was 10.3%.
 
Interstate Banking
 
     The Riegle-Neal Interstate Bank and Branching Efficiency Act of 1994 (IBBA)
permits bank holding companies that are adequately capitalized and managed to
acquire banks located in any other state after September 29, 1995, subject to
certain statewide and nationwide deposit concentration limits. States may also
prohibit acquisition of banks that have not been in existence for at least five
years.
 
     The interstate branching by merger provisions were effective on June 1,
1997, unless a state takes legislative action prior to that date. The long-term
effects on Corus of such changes in interstate banking and branching laws cannot
be predicted. However, it is likely that there will be increased competition
from national and regional banking firms headquartered outside of Illinois.
 
STATISTICAL DATA
 
     Pages 4 through 10 contain supplemental statistical data. This data should
be read in conjunction with Corus' Management's Discussion and Analysis of
Financial Statements and the Consolidated Financial Statements and notes thereto
of the 1998 Annual Report to Shareholders (1998 Annual Report), incorporated
herein by reference in response to Items 7 and 8 hereof.
 
                                        3
<PAGE>   5
 
                     CHANGES IN INTEREST INCOME AND EXPENSE
 
     The following table shows the changes in interest income and expense by
major categories of assets and liabilities attributable to changes in volume or
rate or both, for the periods indicated:
 
<TABLE>
<CAPTION>
                                                       YEAR ENDED DECEMBER 31, 1998
                                                    ----------------------------------
                                                    VOLUME        RATE         TOTAL
                                                    ------        ----         -----
                                                               (THOUSANDS)
<S>                                                 <C>          <C>          <C>
Interest Income:
   Interest-earning deposits with banks.........    $   972      $    (2)     $    970
   Federal funds sold...........................       (839)         (49)         (888)
   Taxable securities other than common
      stocks....................................      9,311         (325)        8,986
   Common stocks................................      1,614         (311)        1,303
   Tax-advantaged securities....................       (105)         (12)         (117)
   Trading account securities...................        334          (42)          292
   Loans, net of discount.......................     (4,410)      (2,449)       (6,859)
                                                    -------      -------      --------
      Net Increase (Decrease)...................      6,877       (3,190)        3,687
                                                    -------      -------      --------
Interest Expense:
   NOW and money market deposits................     (1,133)      (1,761)       (2,894)
   Savings deposits.............................       (365)          38          (327)
   Time deposits................................      9,807          341        10,148
   Short-term borrowings........................       (190)         (49)         (239)
   Federal Home Loan Bank advances..............         --          (44)          (44)
                                                    -------      -------      --------
      Net Increase (Decrease)...................      8,119       (1,475)        6,644
                                                    -------      -------      --------
Decrease in Net Interest Income.................    $(1,242)     $(1,714)     $ (2,957)
                                                    =======      =======      ========
                                                       YEAR ENDED DECEMBER 31, 1997
                                                    ----------------------------------
                                                    VOLUME        RATE         TOTAL
                                                    -------      -------      --------
Interest Income:
   Interest-earning deposits with banks.........    $  (206)     $   (26)     $   (232)
   Federal funds sold...........................      2,865          141         3,006
   Taxable securities other than common
      stocks....................................     (1,602)        (307)       (1,909)
   Common stocks................................      1,481          (73)        1,408
   Tax-advantaged securities....................       (193)          40          (153)
   Trading account securities...................        380          380           760
   Loans, net of discount.......................     (3,211)      (6,880)      (10,091)
                                                    -------      -------      --------
      Net Decrease..............................       (486)      (6,725)       (7,211)
                                                    -------      -------      --------
Interest Expense:
   NOW and money market deposits................       (187)       1,596         1,409
   Savings deposits.............................       (567)          --          (567)
   Time deposits................................      1,201          594         1,795
   Short-term borrowings........................       (494)         229          (265)
   Federal Home Loan Bank advances..............        652           26           678
                                                    -------      -------      --------
      Net Increase..............................        605        2,445         3,050
                                                    -------      -------      --------
Decrease in Net Interest Income.................    $(1,091)     $(9,170)     $(10,261)
                                                    =======      =======      ========
</TABLE>
 
                                        4
<PAGE>   6
 
     The tax-equivalent adjustment for interest income on tax-advantaged loans
and securities is reflected through the rate column based on a marginal
corporate income tax rate of 35%. Volume variances are computed using the change
in volume multiplied by the previous year's rate. Rate variances are computed
using the changes in rate multiplied by the previous year's volume. The change
in interest due to both rate and volume has been allocated between the factors
in proportion to the relationship of the absolute dollar amounts of the change
in each.
 
                              SECURITIES PORTFOLIO
 
Carrying Value of Securities by Category
 
     The carrying value of securities held by Corus were as follows:
 
<TABLE>
<CAPTION>
                                                        DECEMBER 31
                                              --------------------------------
                                                1998        1997        1996
                                                ----        ----        ----
                                                        (THOUSANDS)
<S>                                           <C>         <C>         <C>
Available for sale
   U.S. Government and agencies.............  $529,374    $191,236    $183,404
   Corporate debt securities................    30,173     161,454      95,001
   Common stocks............................   185,698     158,660      92,611
   Other....................................   152,423      20,513       8,013
                                              --------    --------    --------
      Total.................................   897,668    $531,863    $379,029
                                              ========    ========    ========
Held to maturity
   State and municipal......................  $  2,168    $  4,150    $  5,201
   Other....................................     4,442       5,129       6,053
                                              --------    --------    --------
      Total.................................  $  6,610    $  9,279    $ 11,254
                                              ========    ========    ========
</TABLE>
 
Maturities of Securities
 
     The scheduled maturities by security type as of December 31, 1998 were as
follows:
 
<TABLE>
<CAPTION>
                                         FROM        FROM
                                         ONE         FIVE                  NOT DUE AT
                           ONE YEAR    THROUGH      THROUGH      AFTER      A SINGLE
                           OR LESS    FIVE YEARS   TEN YEARS   TEN YEARS    MATURITY     TOTAL
                           --------   ----------   ---------   ---------   ----------    -----
                                                        (THOUSANDS)
<S>                        <C>        <C>          <C>         <C>         <C>          <C>
U.S. Government and
   agencies..............  $529,374    $    --      $    --    $     --     $     --    $529,374
Corporate debt
   securities............    15,302     14,871           --          --           --      30,173
State and municipal......       350        646          672         500           --       2,168
Common stocks............        --         --           --          --      185,698     185,698
Other....................        --         15       12,740     124,047       20,063     156,865
                           --------    -------      -------    --------     --------    --------
         Total...........  $545,026    $15,532      $13,412    $124,547     $205,761    $904,278
                           ========    =======      =======    ========     ========    ========
</TABLE>
 
                                        5
<PAGE>   7
 
     The weighted-average yield for each range of maturities of securities at
December 31, 1998 was as follows:
 
<TABLE>
<CAPTION>
                                               FROM        FROM
                                               ONE         FIVE                  NOT DUE AT
                                 ONE YEAR    THROUGH      THROUGH      AFTER      A SINGLE
                                 OR LESS    FIVE YEARS   TEN YEARS   TEN YEARS    MATURITY    TOTAL
                                 --------   ----------   ---------   ---------   ----------   -----
<S>                              <C>        <C>          <C>         <C>         <C>          <C>
U.S. Government and agencies...    5.03%         --%         --%         --%         --%      5.03%
Corporate debt securities......    6.14        6.09          --          --          --       6.12
State and municipal............   10.55        9.29        7.46        9.37          --       8.94
Common stocks..................      --          --          --          --        2.97       2.97
Other..........................      --        5.50        6.00        5.63        6.81       5.81
</TABLE>
 
     Actual maturities may differ from those scheduled due to prepayments from
issuers. Common stock yields are not considered meaningful for purposes of this
analysis. Yields on tax-advantaged securities reflect a tax equivalent
adjustment based on a marginal corporate tax rate of 35%.
 
                                 LOAN PORTFOLIO
 
Classification of Loans
 
     Corus' loans were as follows:
 
<TABLE>
<CAPTION>
                                                   DECEMBER 31
                          --------------------------------------------------------------
                             1998         1997         1996         1995         1994
                             ----         ----         ----         ----         ----
                                                   (THOUSANDS)
<S>                       <C>          <C>          <C>          <C>          <C>
Commercial real
   estate...............  $  761,564   $  711,495   $  655,793   $  582,331   $  354,893
Student.................     431,304      412,926      402,859      379,129      354,073
Residential first
   mortgage.............     137,683      209,669      286,042      317,787      233,437
Commercial..............     108,759       55,062       61,852       78,469       68,620
Home equity.............      85,408      131,868      188,755      170,793       57,093
Consumer................      26,869       24,955       27,844       30,273       32,393
                          ----------   ----------   ----------   ----------   ----------
         Total..........  $1,551,587   $1,545,975   $1,623,145   $1,558,782   $1,100,509
                          ==========   ==========   ==========   ==========   ==========
</TABLE>
 
Maturities of Loans and Sensitivity to Changes in Interest
 
     The following table classifies the scheduled maturities for the following
loan portfolio categories at December 31, 1998:
 
<TABLE>
<CAPTION>
                                                        FROM
                                         ONE YEAR      ONE TO        AFTER
                                         OR LESS     FIVE YEARS    FIVE YEARS     TOTAL
                                         --------    ----------    ----------     -----
                                                           (THOUSANDS)
<S>                                      <C>         <C>           <C>           <C>
Commercial real estate.................  $241,721     $385,171      $134,672     $761,564
Commercial.............................    70,646       35,622         2,491      108,759
</TABLE>
 
     Of the loans maturing after one year, $269.8 million have fixed rates. To
manage the interest rate exposure of specific, fixed-rate commercial real estate
loans and other loans,
 
                                        6
<PAGE>   8
 
Corus has entered into interest rate swap agreements. For additional information
on such financial instruments, see Note 10 to the Consolidated Financial
Statements on pages 41 through 43 of the 1998 Annual Report, incorporated herein
by reference in response to Item 8 hereof.
 
                      RISK ELEMENTS IN THE LOAN PORTFOLIO
 
Nonaccrual and Past Due Loans
 
     Nonaccrual loans were as follows:
 
<TABLE>
<CAPTION>
                                                             DECEMBER 31
                                        ------------------------------------------------------
                                         1998        1997        1996        1995        1994
                                         ----        ----        ----        ----        ----
                                                             (THOUSANDS)
<S>                                     <C>         <C>         <C>         <C>         <C>
Nonaccrual loans......................  $5,307      $8,641      $7,427      $8,536      $2,389
Nonaccrual loans to total loans.......    0.34%       0.56%       0.46%       0.55%       0.22%
</TABLE>
 
     Interest income that should have been recorded under the original terms of
these loans totaled $405,000 for the year ended December 31, 1998. Total
interest income recorded for these loans in 1998 was $229,000.
 
     Loans past due 90 days or more, including nonaccrual loans, were as
follows:
 
<TABLE>
<CAPTION>
                                                           DECEMBER 31
                                   -----------------------------------------------------------
                                    1998         1997         1996         1995         1994
                                    ----         ----         ----         ----         ----
                                                           (THOUSANDS)
<S>                                <C>          <C>          <C>          <C>          <C>
Loans past due 90 days or more...  $34,877      $41,248      $50,368      $32,714      $20,620
Less guaranteed student loans....   17,543       14,077       15,163       13,913       13,252
                                   -------      -------      -------      -------      -------
Net loans past due 90 days or
   more..........................  $17,334      $27,171      $35,205      $18,801      $ 7,368
                                   =======      =======      =======      =======      =======
   Net loans past due 90 days or
      more as a percentage of
      total loans................     1.12%        1.76%        2.17%        1.21%        0.67%
</TABLE>
 
     Guaranteed student loans that are greater than 90 days past due are
classified as performing due to the principal and accrued interest on such loans
being guaranteed by individual state or private non-profit agencies.
 
Potential Problem Loans
 
     In addition to those loans disclosed under the preceding "Nonaccrual and
Past Due Loans" section, management identified, through their problem loan
identification system, certain other loans in the portfolio that exhibit a
higher than normal credit risk. However, these loans were not classified as
nonperforming loans. These other loans include loans that are past maturity more
than 45 days, have recent adverse operating cash flow or balance sheet trends,
or have general risk characteristics that the loan officer feels might
jeopardize the future timely collection of principal and interest payments. At
December 31, 1998, the principal amount of these loans was $8.5 million. This
amount generally includes loans that were classified for regulatory purposes.
 
                                        7
<PAGE>   9
 
Analysis of the Allowance for Loan Losses
 
     The activity in the allowance for loan losses was as follows:
 
<TABLE>
<CAPTION>
                                                    YEAR ENDED DECEMBER 31
                                      ---------------------------------------------------
                                       1998       1997       1996       1995       1994
                                       ----       ----       ----       ----       ----
                                                          (THOUSANDS)
<S>                                   <C>        <C>        <C>        <C>        <C>
Balance at beginning of year......    $30,660    $32,668    $25,640    $20,157    $19,552
Provision for loan losses.........     10,000     16,000     16,000      5,779         --
Less charge-offs:
   Commercial real estate loans...         18        350        206        284         65
   Student loans..................      1,240      9,707      4,605         81         45
   Residential first mortgage
      loans.......................        414        431          1          4         20
   Home equity loans..............      5,171      8,454      6,421         28         --
   Commercial loans...............          2         22         92        269         35
   Consumer loans.................          7        131         16        153        148
                                      -------    -------    -------    -------    -------
      Total charge-offs...........      6,852     19,095     11,341        819        313
                                      -------    -------    -------    -------    -------
Add recoveries:
   Commercial real estate loans...        166        195      1,026         44        210
   Student loans..................        143         24         80        105        100
   Residential first mortgage
      loans.......................         --          3         --          5          5
   Home equity loans..............      1,553        745        375         --         --
   Commercial loans...............          9         19        770         69        303
   Consumer loans.................         94        101        118        300        300
                                      -------    -------    -------    -------    -------
      Total recoveries............      1,965      1,087      2,369        523        918
                                      -------    -------    -------    -------    -------
Net (charge-offs) recoveries......     (4,887)   (18,008)    (8,972)      (296)       605
                                      -------    -------    -------    -------    -------
Balance at end of year............    $35,773    $30,660    $32,668    $25,640    $20,157
Net (charge-offs)/recoveries to
   average loans Outstanding......     (0.32%)    (1.15%)    (0.56%)    (0.02%)     0.06%
</TABLE>
 
Allocation of the Allowance for Loan Losses
 
     The allocation of the allowance for loan losses was as follows:
 
<TABLE>
<CAPTION>
                                                          DECEMBER 31
                                  -----------------------------------------------------------
                                   1998         1997         1996         1995         1994
                                   ----         ----         ----         ----         ----
                                                          (THOUSANDS)
<S>                               <C>          <C>          <C>          <C>          <C>
Commercial real estate........    $12,971      $ 2,814      $ 2,575      $ 2,934      $ 5,801
Student.......................      2,782        2,658        3,608       11,489        1,202
Residential first mortgage....        459          784        1,034        1,327        2,451
Home equity...................     10,070       16,180       21,460        1,000          827
Commercial....................        269           29           45          445        1,368
Consumer......................        169          306          643          476          291
Unallocated...................      9,053        7,889        3,303        7,969        8,217
                                  -------      -------      -------      -------      -------
Total.........................    $35,773      $30,660      $32,668      $25,640      $20,157
                                  =======      =======      =======      =======      =======
</TABLE>
 
                                        8
<PAGE>   10
 
     The increase in the allocation of the allowance for loan losses from 1997
to 1998 for commercial real estate loans reflects various factors, among them:
(i) commercial real estate construction loans increased to $228 million at
December 31, 1998 from $157 million at December 31, 1997 (refer to page 24 of
the 1998 Annual Report); (ii) unused commitments under existing commercial real
estate lines of credit increased to $243 million at December 31, 1998 from $154
million at December 31, 1997 (refer to page 42 of the 1998 Annual Report); and
(iii) commitment letters outstanding on commercial real estate loans increased
to $373 million at December 31, 1998 from $228 million at December 31, 1997
(refer to page 42 of the 1998 Annual Report).
 
Loan Portfolio Composition
 
     The composition of the loan portfolio was as follows:
 
<TABLE>
<CAPTION>
                                                                  DECEMBER 31
                                                  --------------------------------------------
                                                  1998      1997      1996      1995      1994
                                                  ----      ----      ----      ----      ----
                                                                  (THOUSANDS)
<S>                                               <C>       <C>       <C>       <C>       <C>
Commercial real estate........................     49%       46%       40%       38%       33%
Student.......................................     28        27        25        24        32
Residential first mortgage....................      9        14        18        20        21
Home equity...................................      7         8        11        11         5
Commercial....................................      5         3         4         5         6
Consumer......................................      2         2         2         2         3
                                                  ---       ---       ---       ---       ---
Total.........................................    100%      100%      100%      100%      100%
                                                  ===       ===       ===       ===       ===
</TABLE>
 
     For further review of the loan loss provision and the allowance for loan
losses, reference is made to pages 26 through 27 of Management's Discussion and
Analysis of Financial Statements of the 1998 Annual Report, incorporated herein
by reference in response to Item 7 hereof.
 
                                    DEPOSITS
 
     The scheduled maturities of time deposits in denominations of $100,000 and
greater was as follows at December 31, 1998:
 
<TABLE>
<CAPTION>
                                                          (THOUSANDS)
<S>                                                       <C>
Maturing within 3 months..............................     $ 69,508
After 3 but within 6 months...........................       82,572
After 6 but within 12 months..........................      142,296
After 12 months.......................................      215,918
                                                           --------
   Total..............................................     $510,294
                                                           ========
</TABLE>
 
                                        9
<PAGE>   11
 
                          RETURN ON EQUITY AND ASSETS
 
     The following table presents certain ratios relating to Corus' equity and
assets:
 
<TABLE>
<CAPTION>
                                                                 DECEMBER 31
                                                          --------------------------
                                                          1998       1997       1996
                                                          ----       ----       ----
<S>                                                       <C>        <C>        <C>
Return on average total assets........................     1.7%       1.8%       2.0%
Return on average common shareholders' equity.........    13.7       14.9       20.4
Dividend payout ratio.................................    19.8       19.5       15.4
Average equity to average total assets................    12.2       11.8        9.9
</TABLE>
 
ITEM 2. PROPERTIES
 
     Corus utilizes the building facilities of its Irving Park branch, which is
located at 3959 N. Lincoln Avenue, Chicago, Illinois, for its executive offices.
Corus owns the property and buildings on which nine of the eleven bank branch
locations are located. The other two branch locations are leased from unrelated
parties.
 
ITEM 3. LEGAL PROCEEDINGS
 
     Corus is involved in various legal and regulatory proceedings, many
involving matters that arose in the ordinary course of business. The
consequences of these proceedings are not presently determinable but, in the
opinion of management, these proceedings will not have a material effect on the
results of operations, financial position, liquidity or capital resources of
Corus, except possibly for the matter discussed below.
 
     As disclosed previously, Corus discovered that certain former employees in
the student loan servicing area had falsified some records of telephone calls,
from late 1993 to April 1994, to students whose loans were delinquent. The
telephone calls are a required action to maintain the enforceability of a
student loan's government guarantee. Corus terminated the employees involved and
informed the U.S. Department of Education immediately upon discovery of the
problem and the Department commenced an investigation. The Department's
investigation expanded in 1995 to include a review of whether Corus' student
loan division engaged in improper practices from 1988 to April 1994, including
whether information contained on guarantee claim forms may have been falsified.
 
     Shortly after notifying the Department of the problems in the student loan
servicing area, Corus entered into an interim agreement with the Department
pursuant to which it agreed, pending the conclusion of the investigation, not to
request payment from any guarantor or the Department on any loans that Corus is
unable to state with certainty were not affected by incorrect servicing history
documentation. A total of $14.5 million of loans subject to the interim
agreement were charged-off against the allowance for loan losses since 1996. The
ultimate collectibility of these loans is uncertain.
 
     Although certain employees of Corus may have acted illegally or violated
Department policy or regulations, management is unable to predict what actions,
if any, the Department will take following completion of its investigation, and
cannot estimate the magnitude of the violations or the amount or range of any
liability that Corus will ultimately incur. As such, management is unable to
quantify either the amount of student loans that may lose their
 
                                       10
<PAGE>   12
 
government guarantee or the amount of loans that it may be required to
repurchase and, therefore, the effect such amounts and any related penalties
will have on Corus' financial condition or results of operations. No legal
proceedings have been commenced against Corus as a result of the investigation.
 
     If it is ultimately determined that Corus acted illegally or violated
Department policy or regulations with respect to certain loans in a significant
number of instances or if a settlement is reached, Corus could (i) lose its
government guarantees with respect to certain student loans and (ii) be required
to repurchase a substantial amount of delinquent student loans for which Corus
previously received guarantee payments. In addition, Corus or individual
employees could be subject to substantial penalties. If the Department were to
bring an action, and be successful in proving violations of law related to the
student loan program, potential sanctions could include significant fines,
recovery of treble amounts of guarantee payments incorrectly received by Corus
and the suspension of Corus' continued participation in the student loan
program.
 
     Corus does not condone or permit such improper practices and is cooperating
fully with the Department's investigation.
 
ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS
 
     None.
 
                                    PART II.
 
ITEM 5. MARKET FOR REGISTRANT'S COMMON EQUITY AND RELATED STOCKHOLDER MATTERS
 
PRICE RANGE OF COMMON STOCK
 
     Corus' common stock trades on the NASDAQ National Market tier of The NASDAQ
Stock Market under the symbol: CORS. The high and low prices for the common
stock for the calendar quarters indicated, as reported by NASDAQ, are listed on
page 50 of the 1998 Annual Report, incorporated herein by reference in response
to Item 5 hereof.
 
APPROXIMATE NUMBER OF EQUITY SECURITY HOLDERS
 
     As of February 28, 1999, there were 443 shareholders owning Corus' common
stock, which has a par value of $0.05 per share. Shareholders that own stock in
nominee (i.e., street) name are excluded from the number of security holders of
record.
 
DIVIDENDS ON COMMON STOCK
 
     Quarterly cash dividends per common share for the last two years are
included on page 50 of the 1998 Annual Report, incorporated herein by reference
in response to Item 5 hereof. Dividends were declared and paid on a quarterly
basis. The declaration of dividends is at the discretion of Corus' Board of
Directors and depends upon, among other factors, earnings, capital requirements
and the operating and financial condition of Corus.
 
                                       11
<PAGE>   13
 
ITEM 6. SELECTED FINANCIAL DATA
 
     Refer to page 50 of the 1998 Annual Report, incorporated herein by
reference for additional selected financial data.
 
<TABLE>
<CAPTION>
                                                      DECEMBER 31
                             --------------------------------------------------------------
                                1998         1997         1996         1995         1994
                                ----         ----         ----         ----         ----
                                           (THOUSANDS, EXCEPT PER SHARE DATA)
<S>                          <C>          <C>          <C>          <C>          <C>
Interest income............  $  187,525   $  183,932   $  190,950   $  171,114   $  114,541
Interest expense...........      89,305       82,661       79,611       72,597       45,748
                             ----------   ----------   ----------   ----------   ----------
Net interest income........      98,220      101,271      111,339       98,517       68,793
Provision for loan
   losses..................      10,000       16,000       16,000        5,779           --
                             ----------   ----------   ----------   ----------   ----------
Net interest income after
   provision for loan
   losses..................      88,220       85,271       95,339       92,738       68,793
Noninterest income,
   excluding securities
   gains (losses)..........      20,747       22,032       19,436       15,443       12,572
Securities gains (losses),
   net.....................       4,919        4,881        3,316       (1,332)         663
Noninterest expense........      51,889       51,677       50,181       51,650       45,222
Income tax expense.........      21,369       21,136       24,005       19,429       12,790
                             ----------   ----------   ----------   ----------   ----------
Net income available to
   common shareholders.....      40,628       39,371       43,905       35,770       24,016
                             ==========   ==========   ==========   ==========   ==========
Net income per share:
   Basic...................  $     2.79   $     2.66   $     2.96   $     2.36   $     1.58
   Diluted.................        2.75         2.63         2.93         2.35         1.57
                             ==========   ==========   ==========   ==========   ==========
Cash dividends declared per
   common share............  $    0.555   $    0.530   $    0.480   $    0.360   $    0.300
                             ==========   ==========   ==========   ==========   ==========
Assets.....................  $2,589,415   $2,251,927   $2,218,528   $2,125,092   $1,889,445
                             ==========   ==========   ==========   ==========   ==========
</TABLE>
 
ITEM 7. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
        OF OPERATIONS
 
     The information contained under the caption "Management's Discussion and
Analysis of Financial Statements" on pages 18 through 31 of the 1998 Annual
Report is incorporated herein by reference.
 
ITEM 7a. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK
 
     The information contained under the caption "Risk Management" on pages 27
through 29 of the 1998 Annual Report is incorporated herein by reference.
 
ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA
 
     The consolidated financial statements of Corus, including the notes
thereto, and other information on pages 32 through 50 of the 1998 Annual Report
are incorporated herein by reference.
                                       12
<PAGE>   14
 
ITEM 9. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND
        FINANCIAL DISCLOSURE
 
     On February 12, 1997, the Audit Committee and Board of Directors of Corus
recommended that the shareholders ratify Arthur Andersen LLP at the annual
meeting as independent accountants of Corus for fiscal 1997. This recommendation
caused the dismissal of KPMG LLP (KPMG) as the independent accountants of Corus
upon the completion of the audit of Corus' financial statements as of and for
the year ended December 31, 1996 and the issuance of their report thereon.
 
     For the year ended December 31, 1996, KPMG's reports on the financial
statements did not contain an adverse or a disclaimer of opinion nor were they
qualified or modified as to uncertainty, audit scope or accounting principles.
 
     For the year ended December 31, 1996 and from December 31, 1996 through the
effective date of the dismissal, there were no disagreements between KPMG and
Corus on any matter of accounting principles or practices, financial statement
disclosure, or auditing scope or procedure or any reportable events.
 
     Corus requested that KPMG furnish a letter addressed to the United States
Securities and Exchange Commission stating whether KPMG agrees with the
preceding statements. KPMG's letter dated March 25, 1997 is incorporated by
reference to Corus' Annual Report on Form 10-K for the year ended December 31,
1996.
 
                                       13
<PAGE>   15
 
                                    PART III
 
ITEM 10. DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT
 
     Information regarding directors and executive officers of Corus is
incorporated herein by reference to the descriptions under "Elections of
Directors and Ownership of Shares" on pages 2 through 4 of the 1999 Proxy
Statement. For both those executive officers listed in the Proxy as well as the
other executive officers of the Company (Senior Vice President title and
greater) not listed in the Proxy, the following is a table providing the
executive officer's name, age, position(s) held with the Company and
Subsidiaries and the date the officer assumed their present office(s).
 
EXECUTIVE OFFICERS OF THE REGISTRANT
 
<TABLE>
<CAPTION>
                              POSITION(S) AND OFFICE(S) HELD WITH         ASSUMED
         NAME           AGE      THE COMPANY AND SUBSIDIARIES        PRESENT OFFICE(S)
         ----           ---   -----------------------------------    -----------------
<S>                     <C>   <C>                                    <C>
J.C. Glickman.........  83    Chairman of the Board of the
                              Company                                June 1, 1984
Robert J. Glickman....  52    President and Chief Executive of
                              the Company and Corus Bank, N.A.       June 1, 1984
David H. Johnson,
   III................  44    Executive Vice President of the
                              Company and Chief Operating Officer
                              of Corus Bank, N.A.                    June 10, 1996
Michael G. Stein......  38    Executive Vice President of Corus
                              Bank, N.A.                             February 19, 1996
Timothy H. Taylor.....  34    Executive Vice President and Chief
                              Financial Officer of the Company
                              and Corus Bank, N.A.                   December 1, 1998
Randy P. Curtis.......  40    Senior Vice President of Corus Bank
                              N.A.                                   April 30, 1997
Christopher Glancy....  45    Senior Vice President of Corus
                              Bank, N.A.                             November 15, 1995
Terrence W. Keenan....  53    Senior Vice President of Corus
                              Bank, N.A.                             September 16, 1996
Richard J. Koretz.....  35    Senior Vice President of Corus
                              Bank, N.A.                             November 15, 1995
Joel C. Solomon.......  44    Senior Vice President of Corus
                              Bank, N.A.                             August 29, 1997
</TABLE>
 
ITEM 11. EXECUTIVE COMPENSATION
 
     Information regarding executive compensation is incorporated by reference
to the material under the caption "Executive Compensation" on pages 10 through
18 of the 1999 Proxy Statement.
 
                                       14
<PAGE>   16
 
ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT
 
     Information regarding security ownership of certain beneficial owners and
management is incorporated by reference to the material under the headings
"Outstanding Voting Securities and Principal Shareholders" and "Election of
Directors and Ownership of Shares" on pages 1 through 4, respectively, of the
1999 Proxy Statement.
 
ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS
 
     Information regarding certain relationships and related transactions is
incorporated herein by reference to the material under the heading "Transactions
with Management and Others" on page 20 of the 1999 Proxy Statement.
 
                                    PART IV
 
ITEM 14. EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM 8-K
 
     (a) Exhibits to Consolidated Financial Statements:
 
<TABLE>
<CAPTION>
                                  INDEX                               PAGES
                                  -----                               -----
        <S>                                                           <C>
        Consolidated Balance Sheets...............................       32
        Consolidated Statements of Income.........................       33
        Consolidated Statements of Changes of Shareholders'
           Equity.................................................       34
        Consolidated Statements of Cash Flows.....................       35
        Notes to Consolidated Financial Statements................    36-50
        Report of Independent Public Accountants..................       51
</TABLE>
 
     (b) Reports on Form 8-K:
 
         None.
 
     (c) Exhibit: See exhibit filed herewith
 
                                       15
<PAGE>   17
 
                                 EXHIBIT INDEX
 
<TABLE>
<S>     <C>
(3a)    Amended and Restated Articles of Incorporation is
        incorporated herein by reference to Exhibit 4.1 to the Form
        S-8 filing dated May 22, 1998;
(3b)    By-Laws are incorporated herein by reference to Exhibit 4.2
        to the Form S-8 filing dated May 22, 1998;
(10)    Commercial Loan Officers Bonus Program is incorporated
        herein by reference to Form S-8 filing dated May 22, 1998;
(13)    The portions of Registrant's 1998 Annual Report incorporated
        by reference into Part I or Part II of Registrant's Annual
        Report on Form 10-K for the fiscal year ended December 31,
        1998; and
(16)    Letter regarding change in certifying accountant
        incorporated by reference to the Registrant's Annual Report
        on Form 10-K for the year ended December 31, 1996.
</TABLE>
 
                                       16
<PAGE>   18
 
                                   SIGNATURES
 
     Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the registrant has duly caused this report to be signed on
its behalf by the undersigned, thereunto duly authorized.
 
                                                /s/ TIMOTHY H. TAYLOR
 
                                          --------------------------------------
                                                    Timothy H. Taylor
                                                Executive Vice President &
                                                 Chief Financial Officer
April 30, 1999
 
     Pursuant to the requirements of the Securities Exchange Act of 1934, this
report has been signed below by the following persons on behalf of the
registrant and in the capacities and on the dates indicated.
 
<TABLE>
<C>                                                 <S>                            <C>
             /s/ JOSEPH C. GLICKMAN                 Chairman of the Board of       April 30, 1999
------------------------------------------------    Directors
               Joseph C. Glickman
 
             /s/ ROBERT J. GLICKMAN                 President, Chief Executive     April 30, 1999
------------------------------------------------    Officer & Director
               Robert J. Glickman
 
             /s/ TIMOTHY H. TAYLOR                  Executive Vice President &     April 30, 1999
------------------------------------------------    Chief Financial Officer
               Timothy H. Taylor
 
             /s/ STEVEN D. FIFIELD                  Director                       April 30, 1999
------------------------------------------------
               Steven D. Fifield
 
                /s/ KARL H. HORN                    Director                       April 30, 1999
------------------------------------------------
                  Karl H. Horn
 
               /s/ MICHAEL LEVITT                   Director                       April 30, 1999
------------------------------------------------
                 Michael Levitt
 
             /s/ RODNEY D. LUBEZNIK                 Director                       April 30, 1999
------------------------------------------------
               Rodney D. Lubeznik
 
                /s/ MICHAEL TANG                    Director                       April 30, 1999
------------------------------------------------
                  Michael Tang
 
           /s/ WILLIAM H. WENDT, III                Director                       April 30, 1999
------------------------------------------------
             William H. Wendt, III
</TABLE>
 
                                       17