Pediatric CD8⁺CD56⁺ non-poikilodermatous mycosis fungoides: case report and review of the literature.

Mycosis fungoides (MF) displays a broad spectrum of clinical, histological, and phenotypic variants with different prognostic impact. CD8⁺CD56⁺MF is very rare. So far, only 5 patients with CD8⁺CD56⁺ MF were reported to date. All of the previously described patients with this phenotypic variant were adults at the time of diagnosis and often manifested with widespread poikilodermatous skin lesions. Here we describe the clinicopathological features of a juvenile form of CD8⁺CD56⁺ non-poikilodermatous MF in a 10-year-old girl. In our patient, the disease displayed an indolent course and excellent prognosis with complete remission after treatment with UV light, topical steroids, and methotrexate. The differential diagnosis of CD8⁺ epidermotropic lymphocytic infiltrates in children is discussed, and the cases of CD8⁺CD56⁺ MF reported in the literature are reviewed.