Clinical characteristics and course of CD8+cytotoxic variant of mycosis fungoides: a case series of seven patients

Background Fewer than 5% of cases of mycosis fungoides (MF) present with a cytotoxic/suppressor CD8+ phenotype which, despite immunophenotypic similarities with CD8+ aggressive lymphomas, is regarded as a phenotypic variant of MF. Poikilodermatous MF showing a CD8+ phenotype has been reported to have a nonaggressive clinical behaviour and a good response to psoralen plus ultraviolet A treatment. Objectives To perform a retrospective study of CD8+ MF cases diagnosed in the skin lymphoma clinic of Andreas Sygros Hospital. Methods We analysed the clinical characteristics, the immunophenotypic and molecular indices, as well as the clinical course of these patients. Results Seven cases of CD8+ MF (6 5% of all cases of cutaneous T-cell lymphoma) were diagnosed during 2002-2007. One of seven patients had stage IA, five stage IB and one stage IIB disease. Clinical characteristics were variable: four of seven patients presented with poikilodermatous plaques (in one of them lesions of lymphomatoid papulosis with CD8+ phenotype coexisted), one patient with classic MF, one with plantar MF and one with follicular MF. The time period between disease onset and diagnosis was long for most patients (up to 33 years). All patients received the recommended treatment according to TNM staging. Five of seven patients had complete remission, one partial response and one stable disease. Conclusions Special clinical characteristics, such as hyperpigmentation and poikiloderma, are often noted in CD8+ MF cases. In our series CD8+ MF presented with a long-standing disease and indolent course suggesting that CD8+ cytotoxic immunophenotype may represent a marker of mild biological behaviour.