Hypopigmented mycosis fungoides: a retrospective clinicohistopathologic study

Abstract

Importance: Hypopigmented mycosis fungoides is a rare variant of mycosis fungoides with limited published clinicohistopathologic data available.

Objective: To characterize our patient group, to provide additional information and insight into this malignancy.

Design: A 16-year retrospective medical records review (from 1992 to 2009) was conducted of patients with a diagnosis of hypopigmented mycosis fungoides.

Setting: All patients were seen in the department of dermatology at Howard University Hospital, an outpatient clinic in an urban academic institution.

Participants: The review comprised of 20 patients. Inclusion required presence of hypopigmented skin lesions and a skin biopsy diagnostic for hypopigmented mycosis fungoides.

Interventions: Treatment modalities, including oral psoralen with UVA, narrow-band UVB and/or topical medications such as nitrogen mustard and topical corticosteroids were employed.

Results: Patients ranged from 4 to 57 years old. Fifteen were African American, three African, one Afro-Caribbean and one Hispanic. The interval from disease onset to diagnosis ranged from 7 months to 24 years. Patients presented at Stage 1A or 1B. Treatment included phototherapy and topical medications. In four patients with pre- and post-treatment biopsies, the original histological diagnosis of hypopigmented mycosis fungoides and the subsequent complete resolution were shown. There was no associated mortality in the patients studied.

Conclusions and relevance: Hypopigmented mycosis fungoides affected skin of colour patients in this study. This variant differs from classic mycosis fungoides: younger population, slower progression and the majority of patients remaining in Stage I with treatment. We observed that any repigmentation of lesions suggests an effective treatment regimen, complete repigmentation correlates with clinical and histopathologic resolution, and new hypopigmented lesions during remission suggest relapse. A limitation of this study is the small sample size. This is the first study to correlate the histological resolution of hypopigmented mycosis fungoides with clinical repigmentation of lesions.