Influence of clinicopathologic data on survival was analyzed in 43 patients with cutaneous T-cell lymphoma. The median age was 66 years; 35 were male and eight female. The extent of the disease, established according to a modification of the TNM system, was as follows: T1, three patients; T2, 15; T3, 14; T4, 11; N0, 15; N1, 28; M0, 38; M1, 5; B0, 37; and B1, six. The first treatment applied after staging was skin-limited therapy in seven patients and different regimens of systemic chemotherapy in 29. Seven patients received no treatment or only topical corticosteroids and tars. Median follow-up was 26 months. Nineteen patients died, with a median survival of 36.3 months. The prognostic value of age, sex, delay of diagnosis and staging, pruritus, number of sites of clinically enlarged lymph nodes, results of staging and TNM classification, erythrocyte sedimentation rate, peripheral blood cell count, liver function tests, serum lactate dehydrogenase levels, protein electrophoresis, presence of epidermotropism, thickness of cutaneous infiltrate, blastic cell percentage, mitotic index, cellular density, cutaneous eosinophilia, and follicular mucinosis was studied. Multivariate analysis (proportional hazard model with covariates) indicated that the major prognostic factors in patients with cutaneous T-cell lymphoma are as follows: (1) in a clinical model, the T category of TNM classification and the serum lactate dehydrogenase value; and (2) in a clinicopathologic model, the T category of TNM classification and the thickness of cutaneous infiltrate (measured in 10(-1) mm from the granular layer to the lower limit of the infiltrate) of the clinically thickest lesion.