Thalidomide in Treating Patients With Relapsed or Progressive Systemic Mastocytosis

DISEASE CHARACTERISTICS: * Diagnosis of systemic mastocytosis * Aggressive or borderline (smoldering) disease (in first line or more) * Relapsed or progressive disease * Measurable or evaluable disease * Presence of c-Kit D816V mutation in the skin, spine, or infiltrated organs * No nonsymptomatic mastocytosis PATIENT CHARACTERISTICS: * Life expectancy \> 3 months * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception for 1 month prior to, during, and until first menstrual cycle after completion of study treatment * Bilirubin \< 2 times normal (unrelated to disease) * Liver enzymes \< 2 times normal (unrelated to disease) * Creatinine ≤ 300 mmol/L * No central or peripheral neuropathy leading to psychiatric concerns * No HIV positivity * No active infection or other serious underlying illness that would preclude treatment * No history of thromboembolism or deep vein thrombosis * No geographical, social, or psychological reasons preventing medical monitoring PRIOR CONCURRENT THERAPY: * More than 4 weeks since prior antitumor therapy (e.g., chemotherapy, radiotherapy) * No other concurrent treatment specific for this disease * No concurrent participation in another experimental drug trial