Mycosis fungoides beginning in childhood and adolescence.

Mycosis fungoides is a form of cutaneous T cell lymphoma usually occurring in mid to late adulthood. We report 12 patients with mycosis fungoides whose eruption began before age 20 years, including one patient with histologic documentation at 5 years of age. The onset of mycosis fungoides during the first two decades may be more common than is generally recognized and should be included in the differential diagnosis of chronic dermatoses in children and adolescents.