Folliculocystic and collagen hamartoma of tuberous sclerosis: A new case in a female patient and review of literature.

Folliculocystic and collagen hamartoma (FCCH) of tuberous sclerosis is a rare entity described in 2012 by Torrelo et al. with only 8 cases described, predominantly in males. It presents since birth or early infancy and in the majority of cases is associated with tuberous sclerosis. The hamartoma presents as an exophytic plaque and has distinctive histopathological features including hair follicles, intact or ruptured epidermal cysts, and an increased number of collagen fibers extending to the subcutaneous tissue. Herein we present an additional case of this rare entity in an 18-year-old female who met clinical criteria for tuberous sclerosis. The patient had an exophytic mass in the left temporal area for many years and wanted surgical excision due to its cosmetic appearance. Histopathology of the surgical specimen showed a hamartomatous lesion with multiple large intact epidermal cysts, hairs and increased thickened collagen. The patient has followed up for 1 year after the excision, with no recurrence. Additionally, we provide a literature review of known cases of FCCH as well as its clinical and histopathological differential diagnosis.