Mycosis fungoides (MF), the most common form of cutaneous T cell lymphoma (CTCL), is mainly manifested in the elderly. However, it has been described in children and teenagers.
Objectives: To report six patients with mycosis fungoides diagnosed in patients under 20 years of age. Our focus is on epidemiologic data, clinical features, histopathological aspects, and immunophenotypical findings.
Methods: The files of all patients diagnosed with CTCL at Hospital Universitário Antônio Pedro (HUAP) / Universidade Federal Fluminense (UFF), Niterói, Brazil, from 2007 to 2010 were searched to identify patients under 20 years of age. Slides were reviewed with routine methods (H&E) and immunohistochemical stains by two dermatopathologists and one surgical pathologist.
Results: Among a total of 66 patients with MF, six were children and adolescents between five and nineteen years of age. Most of them had dark skin and presented with the hypopigmented variant of MF; some expressed the T cell CD8+ phenotype, although the prognosis remains the same as for classical CTCL. The main histopathological findings were basilar lymphocytes, Pautrier microabscesses, eccrine infiltration, and dermal fibrosis. One patient had shown pityriasis lichenoides chronica for 10 years before the diagnosis of MF.
Conclusions: The incidence of juvenile mycosis fungoides has increased, corresponding to 9.1 percent of patients diagnosed with MF in our institution in four years. In this sample, 83.3 percent of the patients had the hypopigmented variant and 50 percent of them showed the CD3+/CD8+ T cells phenotype. We emphasize the occurrence of pityriasis lichenoides chronica before the onset of MF in one of our cases. This association, although rare, must be considered in cases of atypical evolution of PLC. The diagnosis of hypopigmented MF should also be considered in patients when hypochromic patches are persistent. We would like to highlight the importance of Pautrier microabscesses, basilar distribution, and eccrine involvement by neoplastic lymphocytes as histopathological diagnostic criteria for this variant of MF.