Lenalidomide Maintenance Post-debulking in Advanced CTCL

DISEASE CHARACTERISTICS: * Diagnoses of advanced T-cell cutaneous lymphoma or mycosis fungoides/Sézary syndrome * Stage IIB-IV disease * Achieved complete or partial response after undergoing prior debulking therapy with 1 of the following recommended\* regimens with or without radiotherapy\*\*: * Gemcitabine hydrochloride IV over 30 minutes on days 1, 8, and 15 of a 28-day course at a dose of 1,000 to 1,200 mg/m² for a total of four courses * Pegylated liposomal doxorubicin hydrochloride IV over 1 hour on days 1 and 15 of a 28-day course at a dose of 20 mg/m² for a total of four courses NOTE: \*These recommended regimens can be altered according to local institutional policies. In case of drug intolerance, the study regimen can be switched from one regimen to the other. NOTE: \*\*Local low-dose/energy-ionizing radiation therapy allowed as part of the debulking process to treat lesions that do not respond after 3 courses of debulking chemotherapy. * Sézary cell burden must be decreased by at least 50% after debulking in patients with Sézary syndrome * Disease not appropriate for skin-directed therapy per local institution standards * No disease progression between registration and randomization * No CNS involvement PATIENT CHARACTERISTICS: * WHO performance status 0-2 * Life expectancy \> 12 months * Hemoglobin ≥ 10 g/dL * Absolute neutrophil count ≥ 1.5 x 10\^9/L * Platelet count ≥ 60 x 10\^9/L * Total bilirubin ≤ 1.5 times upper limit of normal (UNL) * Alkaline…