Forodesine (BCX-1777) in Treating Patients With Refractory Stage IIA, Stage IIB, Stage III, Stage IVA, or Stage IVB Cutaneous T-Cell Lymphoma

DISEASE CHARACTERISTICS: * Histologically confirmed cutaneous T-cell lymphoma * Refractory to prior treatment * Stage IIA, IIB, III, IVA, or IVB disease * Measurable disease PATIENT CHARACTERISTICS: Age * 18 and over Performance status * ECOG 0-2 Life expectancy * At least 3 months Hematopoietic * Not specified Hepatic * AST and/or ALT ≤ 3 times upper limit of normal * Hepatitis B and/or hepatitis C negative Renal * Creatinine clearance ≥ 40 mL/min Immunologic * Human T-cell lymphotrophic virus type I (HTLV-I) negative * HIV negative * No active serious infection not controlled by antibiotics Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No known impaired absorption of the gastrointestinal tract * No other illness that would preclude study participation PRIOR CONCURRENT THERAPY: Biologic therapy * Not specified Chemotherapy * More than 21 days since prior chemotherapy and recovered Endocrine therapy * Concurrent topical corticosteroids allowed provided patient remains on a stable dose Radiotherapy * No concurrent radiotherapy Surgery * Not specified Other * More than 30 days since prior investigational agents and recovered * No concurrent tanning bed use * No other concurrent therapy for cutaneous T-cell lymphoma