Hair follicle nevus: case report and review of the literature.

The study of hair follicle tumors can be confusing, and hair follicle nevi are no exception. Analogous lesions frequently have divergent appellations. We evaluated the English-language literature on hair follicle nevi and histologic equivalents from 1921 to 1994. In addition, we reviewed four standard dermatopathology textbooks for further examples. We found 20 published valid cases of hair follicle nevi. Two of the cases were called congenital vellus hamartoma. Hair follicle nevi are rare, benign, often congenital hamartomas composed of multiple vellus hairs. They are typically on the face. We present an infant girl with a hair follicle nevus and review the histologic features and nomenclature of the lesion.