PXD101 in Treating Patients With Relapsed or Refractory Aggressive B-Cell Non-Hodgkin's Lymphoma

Inclusion Criteria: * Biopsy-proven (no needle aspirations or cytologies) aggressive B-cell non-Hodgkin's lymphoma (NHL), including 1 of the following histology subtypes: * Diffuse large cell NHL * Burkitt's or Burkitt-like NHL * Primary mediastinal NHL * Relapsed or refractory disease * Bidimensionally measurable disease * Transformed NHL allowed * Not eligible for stem cell transplantation (for patients registered to study at first relapse) * No active CNS involvement by lymphoma * Zubrod performance status 0-2 * No history of allergic reactions attributed to compounds of similar chemical or biologic composition to PXD101 * Absolute neutrophil count \>= 1,500/mm\^3 * Platelet count\>=100,000/mm\^3 * WBC \>= 3,000/mm\^3 * Creatinine \< 2 times upper limit of normal (ULN) OR creatinine clearance \>= 60 mL/min * No significant EKG abnormalities * Bilirubin normal * SGOT/SGPT \< 2.5 times ULN (=\< 5 times ULN if liver involvement) * No long QT syndrome or marked baseline prolongation of QT/QTc interval (e.g., repeated demonstration of QTc interval \> 500 msec) * No other significant cardiovascular disease, including any of the following: * Unstable angina pectoris * Uncontrolled hypertension * Congestive heart failure related to primary cardiac disease * Any condition requiring anti-arrhythmic therapy * Ischemic or severe valvular heart disease * Myocardial infarction within the past 6 months * No major surgery within 28 days prior to study entry * No concurrent combination antiretroviral therapy for HIV-positive patients * No concurrent medication that may cause Torsades de Pointes (i.e., prolongation of the QT interval \> 500 msec) * At least 14 days since prior radiotherapy * At least 2 weeks since prior valproic acid or any other histone deacetylase inhibitor * No clinical evidence of any of the following: * Severe peripheral vascular disease * Diabetic ulcers or venous stasis ulcers * History of deep venous or arterial thrombosis within the past 3 months * Radioimmunotherapy is considered a chemotherapy regimen * Single-agent rituximab is not considered a chemotherapy regimen * Standard salvage chemotherapy followed by autologous stem cell transplantation is considered 1 regimen * No known AIDS or HIV-associated complex * Not pregnant or nursing * Fertile patients must use effective contraception * No other malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer or in situ carcinoma of the cervix * At least 2 weeks since prior therapy and recovered * No more than 5 prior chemotherapy regimens