Background: Acral melanomas are uncommon. Due to the thick overlying stratum corneum, accurate estimation of margins is difficult for minimally pigmented or amelanotic melanomas on the palm or sole.
Objective: To describe the use of Mohs micrographic surgery using frozen sections and HMB-45 immunostaining in the treatment of a multiply recurrent acral melanoma that had failed both standard surgery and Mohs surgery.
Methods: The melanoma was excised by Mohs technique, and the margins were checked by frozen section and HMB-45 immunostaining.
Results: The melanoma was completely excised in 11 stages, resulting in a defect that covered much of the plantar surfaces of the ball of the left foot, great, second, third, fourth, and fifth toes. No recurrence has been noted in 22 months of follow-up.
Conclusions: HMB-45 immunostaining is a very valuable adjunct to examination of surgical margins for melanoma, particularly when combined with such histologic features as clustering of cells, melanocyte position within the epidermis, and cytologic atypia.