DISEASE CHARACTERISTICS:

• Histologically confirmed mycosis fungoides or Sezary syndrome

  • Stage IB-IVB disease
  • Must have failed at least one prior systemic therapy
  • Generalized erythroderma allowed

• Measurable disease and at least one indicator lesion OR evaluable disease for erythrodermic patients only

  • Prior radiotherapy to areas of measurable disease allowed if disease progression is present in the site or if measurable disease is present outside irradiation port

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-2 OR
• WHO 0-2

Life expectancy:

• At least 3 months

Hematopoietic:

• WBC at least 3,000/mm^3
• Absolute granulocyte count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3

Hepatic:

• Bilirubin no greater than 2.2 mg/dL
• SGOT or SGPT no greater than 2 times upper limit of normal (ULN)
• Alkaline phosphatase no greater than 2 times ULN

Renal:

• Creatinine no greater than 2.0 mg/dL

Cardiovascular:

• No New York Heart Association class III or IV heart disease
• No clinically significant peripheral venous insufficiency

Other:

• HIV negative
• No poorly controlled diabetes mellitus
• No acute infection requiring IV antibiotics
• No other medical condition that would prevent ingestion or absorption of oral medication
• No other neoplasm within the past 5 years except curatively treated squamous cell or basal cell skin cancer, melanoma in situ, or carcinoma in situ of the cervix
• Not pregnant or nursing
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• At least 4 weeks since prior biologic therapy and recovered
• No concurrent growth factors or epoetin alfa

Chemotherapy:

• At least 4 weeks since prior chemotherapy and recovered

Endocrine therapy:

• At least 4 weeks since prior topical steroids

Radiotherapy:

• See Disease Characteristics
• At least 2 weeks since prior radiotherapy for local control or palliation and recovered

Surgery:

• Recovered from prior major surgery

Other:

• No other concurrent investigational drugs