Calcified Epidermal Cyst on the Neck

The document discussed calcified epidermal cysts, which were rare benign entities first described in 1947. These cysts could appear in various body parts, including the skin, and were characterized by a rock-hard white nodule that might drain white chalky contents. Histologically, they presented as dermal cystic structures filled with keratinous material and calcareous sediments, with a cyst wall of thinned stratified squamous epithelium surrounded by fibrosis. The etiology was controversial, with theories suggesting either dystrophic calcification of preceding epidermal cysts or idiopathic growths. Diagnosis typically involved excisional biopsy and pathologic evaluation, and surgical excision was the preferred treatment to prevent recurrence.