CD8⁺ mycosis fungoides: A low-grade lymphoproliferative disorder

Background The prognosis of the CD8⁺ subtype of mycosis fungoides (MF) is controversial. Although most authors believe that determining the presence of this cell surface antigen has no prognostic value, others have observed a more indolent course for CD8⁺ MF compared with CD4⁺ MF. Objectives To review the cases of CD8⁺ MF in the pediatric and adult populations seen at our institution. Methods This is a retrospective review of clinical and pathologic data. Age, stage at presentation, and outcomes of patients at our institution were compared with those of 2 large MF cohorts that predominantly were CD4⁺ from the relevant literature. Results Sixty-seven patients of a median age of 46 years were included. A higher frequency of early-stage disease was observed for CD8⁺ MF patients at diagnosis when compared with other cohorts, including 31 (47%) patients with stage IA, 33 (50%) with stage IB, and 2 (3%) with stage IIB (P = .001, P = .001, and P = .002, respectively). With a median follow-up (5.5 years, range 0.2-21 years) similar to other cohorts, a higher rate of complete remission was achieved (65.5%, P = .001), and a lower rate of progression was observed (P = .004). Limitations This is a retrospective review. Conclusion Our experience with CD8⁺ MF confirms a more indolent course of disease with this MF variant. Our results warrant a conservative treatment approach limited to skin-directed therapies and observation in most patients.