Hypopigmented mycosis fungoides.

BACKGROUND: Only five cases of purely macular hypopigmented mycosis fungoides have been published in the literature. These patients all had clinical evidence of disease 7 months to 10 years prior to histologic diagnosis, suggesting that this clinical presentation of mycosis fungoides is easily misdiagnosed.

OBSERVATIONS: Three African-American males, ages 9, 15, and 22 years, were found to have mycosis fungoides on evaluation of skin biopsy specimens after initially being clinically diagnosed with, and treated for, pityriasis alba. All three had typical histopathologic changes and cell marker studies showing a relative loss of the CD7 antigen, which is normally present on the majority of T cells. One patient who was treated with methoxsalen plus UV light (PUVA) therapy had clearance of his disease clinically and histologically.

CONCLUSION: From the literature, it would appear that macular hypopigmented mycosis fungoides is exceptionally rare. This perceived rarity may be inaccurate due to either relative underreporting, incorrect diagnoses, or both. From the eight patients now reported to date, it may be said that hypopigmented mycosis fungoides may be seen in nonwhite individuals and more often than not, has onset before age 20 years.