Morphological features and prognostic significance of lesions located on the hands and feet in a large series of patients with mycosis fungoides.

Hand and foot (acral) involvement is uncommon in mycosis fungoides (MF). To determine the frequency, clinical features and prognostic significance of acral involvement in the course of MF. MF subtypes, clinical features of acral lesions, and disease stage were documented retrospectively to assess possible associations. We evaluated 28 consecutive patients with acral involvement in a cohort of 773 MF patients (3.6%) over 24 years. The median age of acral involvement was 55 years. None of the patients exhibited isolated acral involvement. In 53.6% of patients, acral lesions were present at the time of MF diagnosis. Classic MF (71.4%) was the most common subtype, followed by folliculotropic (32.2%). The plantar region was the most common localization of acral involvement (53.6%), presenting typically with erythematous squamous/hyperkeratotic papules or plaques, tumours, and diffuse micropapular lesions with erosions. The dorsum of the hand and foot, and palms were mostly involved with tumoral lesions and/or erythematous squamous plaques. Although 64.3% of patients were diagnosed with early-stage MF, most of them (75%) exhibited advanced-stage disease during the course. All lesions in the acral location were associated with the involvement of other body parts in our cases. They occurred with a relatively higher ratio in folliculotropic MF. Acral lesions display a diverse clinical spectrum, including grouped micropapular lesions with erosions in the plantar region. Considering the high rate of advanced-stage cases, acral involvement seems to be an independent risk factor for disease progression in MF.