DISEASE CHARACTERISTICS:

• Histologically confirmed solid tumor or lymphoma

  • Metastatic, progressive, refractory, or unresectable disease
  • Not amenable to standard curative measures
• No known brain metastases

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2

Life expectancy

• More than 3 months

Hematopoietic

• Absolute neutrophil count ≥ 1,500/mm^3
• Platelet count ≥ 100,000/mm^3
• WBC ≥ 3,000/mm^3
• Hemoglobin > 9 g/dL

Hepatic

• Bilirubin ≤ 1.5 times upper limit of normal (ULN)
• AST and ALT ≤ 2.5 times ULN
• No suspected Gilbert's syndrome

Renal

• Creatinine ≤ 1.5 times ULN OR
• Creatinine clearance ≥ 60 mL/min

Cardiovascular

• No symptomatic congestive heart failure
• No unstable angina pectoris
• No unstable cardiac arryhthmia

Gastrointestinal

• Able to take and retain oral medications
• No malabsorption problems
• No acute or chronic gastrointestinal condition

Other

• Not pregnant or nursing
• Negative pregnanct test
• Fertile patients must use effective double-method contraception 1 month before, during, and 3 months after study treatment
• No known HIV positivity
• No weight loss > 10% within the past 2 months
• No history of allergic reaction attributed to compounds of similar chemical or biologic composition to MS-275 or isotretinoin
• No other uncontrolled illness
• No ongoing or active infection
• No seizure disorder
• No psychiatric illness or social situation that would preclude study participation

PRIOR CONCURRENT THERAPY:

Biologic therapy

• More than 4 weeks since prior anticancer vaccine therapy
• More than 4 weeks since prior anticancer immunotherapy
• No concurrent anticancer vaccine therapy
• No concurrent anticancer immunotherapy

Chemotherapy

• More than 4 weeks since prior anticancer chemotherapy (6 weeks for nitrosoureas, mitomycin, or other agents known to cause prolonged marrow supression)
• No concurrent anticancer chemotherapy

Endocrine therapy

• More than 4 weeks since prior anticancer hormonal therapy except gonadotropin-releasing hormone (GnRH) agonist therapy for non-castrated patients with prostate cancer
• Concurrent GnRH agonist therapy for non-castrated patients with prostate cancer allowed
• Concurrent luteinizing hormone-releasing hormone agonist therapy allowed provided there is evidence of tumor progression
• Concurrent adrenal steroid replacement therapy allowed
• No concurrent ketoconazole as second-line hormonal treatment for prostate cancer
• No concurrent corticosteroids except for treatment of refractory nausea or vomiting
• No other concurrent anticancer hormonal therapy

Radiotherapy

• More than 4 weeks since prior anticancer radiotherapy
• More than 2 weeks since prior palliative radiotherapy
• No concurrent anticancer radiotherapy

Surgery

• More than 4 weeks since prior major surgery

Other

• Recovered from all prior therapy
• No prior MS-275

• No prior oral isotretinoin

  • Isotretinoin for the treatment of acne allowed provided > 3 years since prior administration
• More than 4 weeks since other prior anticancer therapy
• No concurrent tetracycline
• No concurrent high-dose vitamin A
• No concurrent valproic acid
• No other concurrent investigational agents
• No other concurrent anticancer therapy