Primary cutaneous small/medium CD4+ T-cell lymphomas: a heterogeneous group of tumors with different clinicopathologic features and outcome.

To define the clinical and pathologic characteristics of primary cutaneous small/medium CD4(+) T-cell lymphoma (PCSM-TCL) and identify parameters of prognostic significance. We have investigated 24 patients with primary cutaneous lymphomas composed of small/medium mature T-cells with a betaF1, CD3, CD4(+) and/or noncytotoxic, CD8(-) and CD30(-) phenotype. The proliferation index and CD8(+) infiltrating cells were quantified with an automated image analysis system. Sixteen patients presenting with solitary or localized plaques or small nodules (< 3 cm) had an indolent course. Only three patients experienced repeated cutaneous relapses, and none of them died as a result of the disease after 1 to 168 months (median, 17 months) of follow-up. The tumors had a low proliferation (median Ki-67, 9% +/- 5%) and an intense infiltrate of reactive CD8(+) (median, 20% +/- 11.7%). Five patients presenting with rapidly evolving large tumors or nodules (>/= 5 cm) had an aggressive disease and died with extracutaneous dissemination 18 to 36 months after diagnosis (median, 23 months). These tumors had a significantly higher proliferation (median Ki-67, 22% +/- 11.3%; P < .05) and lower number of infiltrating CD8(+) (median, 1% +/- 3%; P < .05) than the previous group. A third group of three patients had a peculiar clinical presentation with multifocal relapsing lesions without extracutaneous dissemination after a long period of follow-up ranging from 41 to 92 months. Histologically, these cases had an intense infiltrate of eosinophils. PCSM-TCL is a heterogeneous group of tumors with differentiated clinical and pathological characteristics with impact in the outcome of the patients.