Extra-testicular Intra-scrotal Median Raphe Epidermoid Cyst Mimicking Polyorchidism in a Child

Abstract

Epidermoid cysts are encapsulated sebaceous cysts that contain keratin. They present at any age, yet they are commoner in adults. They mainly affect face, neck, trunk and to a lesser extent groin, but can potentially arise as a subepidermal nodule anywhere on the body. They develop from the follicular infundibulum, and are different from dermoid cysts as epidermoid cysts do not contain other adnexal structures of embryonic origin. Epidermoid cysts are mostly silent but can rupture, get inflamed, become infected or develop daughter cysts. Very rarely epidermoid cysts develop in proximity to testicles. They can be mistaken for a testicular tumor. The pre- operative diagnosis is essential to avoid unindicated testicular surgery. Magnetic resonance imaging (MRI) is vital for diagnosis. We report a 6-year-old child with a long standing painless scrotal swelling thought by the parents to be polyorchidism. They were alarmed by its recent rapid growth. By examination it was a median raphe cyst. Pre-operative imaging and operative surgical removal proved it to be an inflamed epidermoid cyst. The surgery was uncomplicated and the child had an uneventful recovery. Testicular epidermoid cysts in children are exceptionally rare, yet they can present as median raphe cysts. Inflammation within the epidermoid cyst presents clinically as rapid painless growth. Clinical examination, high index of suspicion and pre-operative MRI avoid unnecessary testicular surgery.

Keywords

• epidermoid cyst
• children
• polyorchidism
• painless scrotal swelling