Juvenile Onset Hypopigmented Mycosis Fungoides: A Case Series Of 3 Patients

Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma (CTCL). Primary cutaneous lymphomas (PCLs) are exceedingly rare in children and adolescents, with mycosis fungoides (MF) being the most frequent PCL diagnosed in childhood. The incidence of MF is 6.4 per 1, 000, 000 per year in adults, but the occurrence in children and young adults is rare and has not been well established yet. Hypopigmented mycosis fungoides (HMF) is an atypical and rare subtype of MF characterized by solely hypopigmented patches or in combination with erythematous patches or plaques. There are no criteria that define a typical case of HMF. We present three cases of juvenileonset HMF at Department of Dermatology and Venereology, University Hospital Center Zagreb between November 2014 and January 2015. Patients were between 9 and 12 years old at the time of diagnosis. The diagnosis was reached based on clinical, histopathological and immunohistochemical correlation. All patients were investigated at the time of diagnosis with complete blood count, peripheral smear, ultrasonography of abdomen and pelvis, and chest X-ray. They were all without extracutaneous progression of disease. Narrowband UVB (311nm) phototherapy and/or potent topical steroids were used as a first- line treatment. HMF is rare in Caucasians and with only few cases described in children. Juvenile-onset MF is often misdiagnosed at early stages as benign condition. HMF may simulate atopic dermatitis, pityriasis alba, pityriasis lichenoides, tinea versicolor, vitiligo, postinflammatory hyperpigmentation or leprosy (Hansen? disease). Although HMF has good prognosis, it is a malignant skin lymphoma and should always be treated as such. Treatment modalities for juvenile MF are based on general strategies for adults according to disease stage.