Biopsy of a 5 mm cystic lesion on the right heel of a 48-year-old woman.

An excisional biopsy of an asymptomatic cystic lesion that had been present for several years on the right heel of a 48-year-old woman revealed a subcutaneous cyst lined by ciliated columnar epithelium. On immunostaining, the epithelial cells were positive for Pan-cytokeratin (CK AE 1/3), estrogen receptor (ER) and progesterone receptor (PR), but negative for carcinoembryonic antigen (CEA), suggesting Mullerian type of epithelium. Cutaneous ciliated cyst of Mullerian type occurs almost exclusively on the lower extremity of premenopausal women. The lesion is benign and excision is curative.