The standard treatment for patients with HL that has not responded to treatment or has come back after treatment is stem cell transplant. When patients are not eligible for transplant or when HL comes back after transplant, there are no standard treatment options. These patients can receive chemotherapy or participate in clinical trials. Bendamustine HCl is a chemotherapy agent that is effective in treating patients with various diseases, including non-Hodgkin's lymphoma, multiple myeloma, and breast cancer. It was recently approved for the treatment of chronic lymphocytic leukemia. In addition, small studies from Eastern Europe have shown that bendamustine HCl is likely effective for treating HL. This study will find out the effect of bendamustine HCl for transplant-ineligible patients with HL that has not responded to or has come back after treatment.

Inclusion Criteria:

• Histologic diagnosis of Classical Hodgkin lymphoma, confirmed by the department of hematopathology at MSKCC. Patients who have relapsed after an autologous stem cell transplant must have a biopsy after transplant to confirm relapsed Hodgkin's disease. Patients who have relapsed after an allogeneic transplant must also have a biopsy posttransplant.
• Age > or = to 18
• All patients must have PET avid measurable disease.
• Last chemotherapy > or = to 4 weeks from the start of Bendamustine HCl
• Receiving no other treatment for HL
• Patients must have normal baseline cardiac function based upon echocardiogram or gated blood pool scan (MUGA) with an ejection fraction > or = to 50%
• Patients must have a serum creatinine of < or = to 1.5 mg/dl; if creatinine >1.5 mg/dl creatinine clearance must be >60 ml/minute.
• Patients must have ANC>1000/mcl and Platelets>100,000/mcl.
• Patients must have a bilirubin level of < 2.0 mg/dl in the absence of a history of Gilbert's disease (or pattern consistent with Gilbert's).
• Patients must be Hepatitis B surface antigen and Hepatitis B core antibody negative and Hepatitis C negative.
• Patients must have failed an autologous stem cell transplant or be ineligible for an autologous stem cell transplant due to chemo-refractory disease(as defined as <50% response to standard salvage chemotherapy).
• Women who are pre-menopausal must have a negative pregnancy test
• Subjects must agree to use appropriate contraception until 4 weeks after the completion of chemotherapy.
• Patients must be HIV negative.
• If patients have a history of malignancy other than cutaneous basal cell or squamous cell carcinoma, they must be disease-free for ≥ 5 years at the time of enrollment.
• Patients or their guardians must be capable of providing informed consent.

Exclusion Criteria:

• Patients with either parenchymal brain or lepto-meningeal involvement.
• 7 or more consecutive days of prednisone therapy prior to therapy.
• Known pregnancy or breast-feeding.
• Medical illness unrelated to HL, which in the opinion of the attending physician and principal investigator will preclude administration of chemotherapy safely. This includes patients with uncontrolled infection, chronic renal insufficiency, myocardial infarction within the past 6 months, unstable angina, cardiac arrhythmias other than chronic atrial fibrillation and chronic active or persistent hepatitis
• History of any malignancy for which the disease-free interval is <5 years, excluding curatively treated cutaneous basal cell or squamous cell carcinoma and carcinoma in-situ of the cervix.
• Relapse <6 months post allogeneic stem cell transplant