Study of Pegylated Interferon-Alfa 2b in Combination With PUVA Therapy In CTCL

DISEASE CHARACTERISTICS: * Histologically confirmed mycosis fungoides/Sezary syndrome * Stage IB-IVA disease * Erythrodermic disease allowed * Measurable disease * One or more indicatory lesions must be designated prior to study entry PATIENT CHARACTERISTICS: * ECOG/WHO performance status 0-1 * Life expectancy ≥ 3 months * Absolute neutrophil count ≥ 1,500/mm³ * Platelet count ≥ 75,000/mm³ * WBC ≥ 3,000/mm³ * Serum creatinine ≤ 2.0 mg/dL * Total serum bilirubin ≤ 2.2 mg/dL * Serum AST and ALT ≤ 2 times upper limit of normal * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * Patients must be disease free of prior malignancies for ≥ 5 years except currently treated squamous cell or basal cell carcinoma of the skin, carcinoma in situ of the cervix, or surgically removed melanoma in situ of the skin (stage 0), with histologically confirmed free margins of excision * No history of seizure disorder or severe heart disease * No acute infections * Diagnosed depression allowed with receiving appropriate care for depression PRIOR CONCURRENT THERAPY: * No prior psoralens with ultraviolet light A or interferon alfa therapy * More than 4 weeks since prior topical therapy, systemic chemotherapy, or biologic therapy * More than 4 weeks since prior surgery and fully recovered * At least 1 week since prior antibiotics * No other concurrent standard or investigational topical and systemic antipsoriatic or anticancer therapies including radiation, steroids, retinoids, nitrogen mustard, thalidomide, or other investigational agents * No concurrent topical agents except emollients