Epidermoid Cyst (back)

Diagnosis: Epidermoid Cyst (back)

Slightly blue, firm, round nodules with a central punctum.

Clinical Presentation

Slightly blue, firm, round nodules with a central punctum.

Clinical History

Submitted by Alaa Saad. Originally posted October 14, 2010.

Treatment

See case discussion.

Differential Diagnosis

• Pilar (trichilemmal) cyst • Lipoma • Dermoid cyst • Abscess • Dermatofibroma • Pilomatricoma

Key Learnings

• Most common cutaneous cyst — lined by stratified squamous epithelium with granular layer • Central punctum is a helpful clinical clue • Rupture → intense foreign body reaction — NOT infection in most cases • Multiple epidermoid cysts: consider Gardner syndrome (APC mutation) • Pilar cyst: scalp predilection, lacks granular layer

Tags: epidermoid, cyst, back, alaa saad