Korean J Dermatol.  2022 Mar;60(3):173-177.

A Rare Case of Pigmented Median Raphe Cyst

• Kim HH
• Myung KB
• Kwon ES
• Cheong SH

Abstract

Median raphe cysts (MRCs) are rare benign lesions that occur as a result of congenital defects during the embryological development of the male genitalia in the fetal period. It can develop anywhere along the midline, from the meatus to the anus. Pigmented MRCs are rare subtypes that contain melanin pigments or melanocytes in the epithelium, and there are only eight such cases reported worldwide. We report herein a case of pigmented MRC in the perineum of a 3-year-old boy. The clinical features include a linear tubular structure and foreign body granuloma at the tip of the linear cystic lesion and rare histological findings of pigmented cuboidal epithelium and squamous epithelium. Immunohistochemical staining revealed strong positivity for c-kit in the pigmented cuboidal epithelium. In this report, we discuss a rare case of pigmented MRC with a mixed type of squamous epithelium and pigmented cuboidal epithelium and review the associated literature.

Keyword

Median raphe cyst; Perineum