Juvenile-Onset Early-Stage Mycosis Fungoides-Associated Follicular Mucinosis: A Case Report.

We report a juvenile case of mycosis fungoides with prominent follicular mucinosis (FM). The patient was a 9-year old boy who presented with a 2-month history of enlarging alopecic patch with fine scales on the scalp. Dermatologic examination revealed orange-tan slightly palpable plaques with follicular prominence on his trunk. The patient and his family were not aware of these asymptomatic truncal plaques. Histopathologic examination of both-scalp and trunk-lesions revealed folliculotropic lymphocytic infiltration with mucin. Immunohistochemical study showed that lymphocytic infiltration was CD4 dominant. Flow cytometry analyses of peripheral blood were normal. Any abnormal populations and Sézary cells were not observed on blood smear. Polymerase chain reaction testing showed monoclonality for the T-cell receptor4-[Latin Small Letter Rams Horn] gene. Our patient had the clinical and histopathological diagnosis of follicular mycosis fungoides-associated follicular mucinosis.