Track

Case Reports

Abstract

Folliculocystic and collagen hamartoma (FCCH) is a very rare cutaneous manifestation and first described in 2012 in patients with tuberous sclerosis complex (TSC).   Histologically, it is characterized by comedo‑like infundibular cysts, dense collagen deposition, and concentric perifollicular fibrosis. Only a handful of cases, fewer than 20 worldwide, have been documented, typically in male TSC patients and often presenting as solitary lesions.

We report an unusual presentation in a 13‑year‑old girl with TSC2 [c.2251 C>T, p.R751X mosaic] mutation, who had two distinct, asymptomatic, skin‑colored plaques on her scalp. The first measured, 1.5 cm in diameter, located on the right upper forehead and by report was present since birth with very minimal growth. The second larger lesion appeared on the right frontal scalp, approximately one year ago and rapidly enlarged to a size of 3 cm. Both plaques were excised and histopathology revealed classic FCCH features in both lesions with infundibular dilatation with comedone‑like openings, dense dermal collagen extending into the subcutaneous tissue, perifollicular fibrosis, and capillary dilation, supporting the diagnosis of FCCH.

This dual scalp presentation in a female, especially with one congenital and one later‑emerging lesion deviates markedly from the predominantly male, solitary, infancy‑onset pattern previously described in the literature. It underscores broader phenotypic variability and suggests FCCH may be under‑recognized in female TSC patients. By documenting multiple lesions in an adolescent girl, this case expands the known demographic and clinical spectrum of FCCH, reinforcing its potential role as a distinctive, though uncommon, cutaneous hallmark of TSC.