Recurrent Spitz's nevi. A clinicopathologic investigation.

Spitz's nevi recur uncommonly following initial removal. A clinicopathologic investigation was performed on 16 such cases. The initial nevi in almost all cases extended to the margins of the sections. Otherwise, these lesions showed no unusual clinical or histologic features. The average recurrence time was 13 months, with a range from 2 months to 3 years. The recurrent lesions occasionally were mistaken clinically for keloids. Histologically, recurrent lesions were predominantly intradermal. Nests, fascicles, and individual spindle and/or epithelioid cells extended to the deep reticular dermis and occasionally into the subcutaneous fat. The surrounding stroma was densely fibrotic. Recurrent Spitz's nevi are different clinically and histologically from recurrent ordinary melanocytic nevi. They also often differ histologically and clinically from primary Spitz's nevi. Recurrent Spitz's nevi are similar histologically to the desmoplastic type of Spitz's nevus.