This research study will use a type of drug called anti-IL-6 antibody, also known as CNTO 328. An antibody is a substance in the body that fights infection. CNTO 328 is an investigational drug that has been shown to slow down tumor growth or shrink tumors when tested in animals. In a previous clinical trial in patients with multiple myeloma (blood cancer), CNTO 328 appeared to be a potent inhibitor of IL-6 . One study has been completed for kidney cancer. There are studies ongoing in humans with multiple myeloma and prostate cancer to see if CNTO 328 is safe and to see what effects it has on these types of cancer. This is an open-label, nonrandomized, dose-finding phase 1 study with CNTO 328 in patients with B- cell non-Hodgkin's Lymphoma, Multiple Myeloma, or Castleman's disease. The purpose of this study is to evaluate different doses and schedules of CNTO 328 to see which dose/schedule is safe. CNTO 328 will be given through a small tube that goes directly into your vein, called an intravenous (IV) infusion. Depending on when the patient enters the study, the patient will be assigned to receive one course of CNTO 328 in one of the following groups: Group 1: 3 mg/kg 2 hr IV infusion every 2 weeks for 4 doses. Group 2: 6 mg/kg 2 hr IV infusion every 2 weeks for 4 doses. Group 3: 12 mg/kg 2 hr IV infusion every 3 weeks for 3 doses. Group 4: 6 mg/kg 2 hr IV infusion every week for 7 doses. Group 5: 12 mg/kg 2 hr IV infusion every 2 weeks for 4 doses. Group 6: 12 mg/kg 1 hr IV infusion every 3 weeks for 3 doses. Group 7a: 9 mg/kg 1 hr IV infusion every 3 weeks. Group 7b: 12 mg/kg 1hr IV infusion every 3 weeks for Castleman's patients only. In Groups 1-5, the overall amount of study drug that will be given increases with each higher group. Group 1 will be filled before Group 2 starts and Group 2 will be filled before Group 3 starts, etc. In this way, CNTO 328 can be tested more safely. Both the patient and the study doctor will know to which group the patient is assigned. Patients will remain in the group that they are assigned to for the entire time of participation in the study. Up to 70 patients may take part in this study. Patients in Groups 1-6 will be in the study for up to 34 weeks prior to Post Study Follow-Up. Screening: up to 4 weeks before the first dose schedule of CNTO 328. Treatment: up to 6 weeks of treatment with CNTO 328. Extended Dosing: Patients assigned to Groups 1-6, and their cancer or disease has become stable or better while receiving CNTO 328, may be able to receive additional courses of study drug. Patients in Group 7 will be in the study until their disease gets worse, they can no longer tolerate CNTO 328, the study doctor feels it is in their best interest to stop CNTO 328 or they longer wish to participate in the study. Long Term Follow-Up: Patients will be contacted by telephone every six months after the last infusion of study drug to assess the patient's disease status and survival. Dose (6-12 mg/kg) and frequency (weekly or 2 or 3 week intervals) of dosing depends upon Group assignment. CNTO 328 will be given through a small tube that goes directly into your vein, called an intravenous (IV) infusion. The infusion will take about 2 hours to complete for groups 1-5 and 1 hour for Groups 6 and 7. In Groups 1-6, CNTO 328 will be given once every 1, 2 or 3 weeks from days 1 to 43 depending on treatment assignment. In Group 7a and Group 7b, CNTO 328 will be given on day 1 of each 21 day cycle.