Long-term follow-up and management of small and medium-sized CD4+ T cell lymphoma and CD8+ lymphoid proliferations of acral sites: a multicenter experience.

BACKGROUND: Primary cutaneous CD4+ small-medium pleomorphic T cell lymphoma (SMPTCL) is a low-grade cutaneous T cell lymphoma. Its clinical and histopathologic features are comparable with those of CD8+ lymphoid proliferations (LPs) of the ear and acral sites.

OBJECTIVES: We performed a retrospective analysis of patients with CD4+ SMPTCL or CD8+ LP to elucidate the clinical course, prognosis, and outcomes.

METHODS: Demographic, clinical, and treatment data were reviewed. Histopathologic data based on architectural, cytomorphologic, and immunohistochemical features were assessed. Immunohistochemical staining for T and B cell markers was evaluated.

RESULTS: A total of 25 patients including 22 with CD4+ SMPTCL and three with CD8+ LP were identified. All patients presented with a single lesion, predominantly on the head, neck, or upper trunk (84%). No patients showed extracutaneous disease at any evaluation. The most common histopathologic changes showed a dense nodular infiltrate of small cells with hyperchromatic nuclei without significant follicular or adnexal involvement. Patients were treated with excision (48%), local radiation (28%), or topical or intralesional steroids (24%). All patients achieved complete resolution of disease. Five patients demonstrated cutaneous relapse at new sites.

CONCLUSIONS: The CD4+ SMPTCL/CD8+ LP subgroup usually presents with solitary lesions and demonstrates an indolent clinical course. Typical presentation, classic histopathology, widespread expression of follicular T helper cell markers, and loss of a T cell antigen are diagnostic features of CD4+ SMPTCL, whereas monomorphous CD8+ infiltrate without follicular T helper cell markers is consistent with CD8+ LP. Local skin-directed therapy is appropriate in these patients.