Case of dystrophic calcinosis cutis in epidermal cyst arising from verrucous epidermal nevus.

Dystrophic calcinosis cutis is diagnosed when calcium is deposited into previously damaged tissue by connective tissue disease, panniculitis, pseudoxanthoma elasticum or trauma. We report a case of dystrophic calcinosis cutis arising from the lesion of an epidermal cyst on the verrucous epidermal nevus. A 20-year-old woman presented with a polypoid pinkish tumor on a brownish, verrucous plaque. Histopathological findings of the pinkish tumor showed calcium deposits as amorphous, basophilic material lining the true epidermis in the upper dermis, which were compatible with dystrophic calcinosis cutis and the plaque was diagnosed as a verrucous epidermal nevus.