Fibrofolliculoma: solitary and multiple types.

Multiple skin tumors generally show autosomal dominant inheritance and are sometimes associated with other cutaneous and internal lesions. Solitary growths are typically nonhereditary and unassociated with other abnormalities. We found only two previous reports of solitary fibrofolliculoma and only one of multiple fibrofolliculomas without associated lesions; a few publications describe multiple fibrofolliculomas in patients with perifollicular fibromas, trichodiscomas, acrochordons, and connective tissue nevus. We studied five new cases of solitary nonhereditary fibrofolliculomas and one of multiple familial fibrofolliculomas without associated lesions. Clinically, fibrofolliculomas were typically small growths with a central dilated follicle containing horny material. Histologically, there was characteristically a hyperplastic follicular infundibulum with a central keratinous plug, and anastomosing strands of basaloid cells branching into an angiofibromatous stroma. Fibrofolliculoma is thus another skin tumor in which patients with multiple growths showing autosomal dominant inheritance sometimes have associated abnormalities, while solitary lesions with identical clinical and microscopic features are relatively trivial and nonhereditary.