Mycosis fungoides in patients under 20 years of age: Report of 7 cases, review of the literature and study of the clinical course

Background: Mycosis fungoides (MF) is rare in young patients. Its clinical behavior is still uncertain, as some reports have suggested that it has a m ore aggressive course than does the adult-onset type. Aim: To ascertain if early-onset MF represents a heterogeneous group of cutaneous T cell lymphom as. Materials and Methods: Clinical, immunohistopathological and follow-up data of early-onset (<20 years of age) MF cases reported in the literature (n = 42) plus 7 described herein were compared with those of a cohort of ad ult-onset MF patients (n = 252) diagnosed at our institution since 1975. Re sults: The majority of the 49 early-onset MF patients had patch-plaque stag e disease at diagnosis, Ten had hypopigmented lesions. The predominant phen otype was CD3+ CD4+CD7-CD8-, Seven patients had a stage progression, 6 with extracutaneous involvement. Five- and 10-year survival rates were 93 and 7 4%, respectively, Conclusions: No statistically significant differences wer e found in the disease course between early- and adult-onset MF.