A young woman had diffuse follicular hamartoma that later in life was complicated by development of secondary follicular tumors (multiple proliferating trichilemmal cysts) and extensive inflammation leading to development of scarring alopecia. In addition, her palms and soles were involved by numerous discrete pits and punctate keratoses. Histologic changes of the palmoplantar lesions consisted of funnelshaped dilatation of the intra-epidermal and dermal portions of the eccrine sweat ducts. Dilated ducts were plugged with a columnar mass of parakeratotic material containing acid mucopolysaccharide and foci of calcification.
Mehregan AH, Hardin I. Generalized Follicular HamartomaComplicated by Multiple Proliferating Trichilemmal Cysts and Palmar Pits. Arch Dermatol. 1973;107(3):435-438. doi:10.1001/archderm.1973.01620180085028