Characteristic cytogenetic aberrations are found in the various histopathological designations of @entity1653 . These aberrations range from the loss of 22q in histologically benign @entity5 to complex hypodiploid karyotypes in atypical and @entity5 . This progression is characterized by increasing chromosome loss and instability, with a critical step being the loss of 1p. We report a detailed cytogenetic investigation of chromosome aberrations in a series of 88 @entity1653 using Giemsa banding and multicolor spectral karyotyping (SKY). Clonal chromosome aberrations were identified in 46 (52%) @entity5 by G banding. Thirty-five @entity5 showing complex chromosome aberrations not fully characterized by G banding were subsequently reanalyzed by SKY. The SKY technique refined the G-band findings in 18 (51%) of the @entity5 on which it was applied. The most common features of cytogenetic progression in the complex karyotypes were chromosome arm-specific losses relating to the formation of deletions and dicentric chromosomes involving 1p. Part or all of 1p was lost in 19 @entity5 . @entity5 showed evidence for the loss of 1p in a progressive step-wise series of telomeric fusions involving the formation of unstable intermediates. Five recurring dicentric chromosomes were identified, including dic (1;11)(p11;p11), dic(1;12)(p12 approximately p13;p11), dic(1;22)(p11;q12 approximately q13), dic(7;19)(p11;p11), and dic(19;22)(p11 approximately p13;q11 approximately q13). These findings provide evidence that telomeric fusions play a role in the formation of clonal deletions, dicentrics, and unbalanced translocations of 1p. The loss of 1p has possible diagnostic and prognostic implications in the management of @entity1653 .

Telomeric fusion as a mechanism for the loss of 1p in XXXX .

@entity5 :: ('MESH:D009369', 'Disease') :: ['Five tumors', 'malignant tumors', 'tumors'] @entity1653 :: ('MESH:D008579', 'Disease') :: ['meningioma', 'meningiomas']
@entity1653 :: (MESH:D008579,Disease) :: ['meningioma']
