Hypopigmented mycosis fungoides: a retrospective clinicohistopathologic study

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

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

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

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

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

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

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.

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.