Cutaneous ciliated cyst on the cheek in a male

A 53‐year‐old man presented with a 2‐year history of a painless mass on the right cheek. On physical examination, the lump was a solitary, well‐demarcated, mobile lesion. There was no abnormality in the surrounding skin. Ultrasonography demonstrated a single, cystic, well‐defined, subcutaneous cyst, measuring 20 mm in diameter. Laboratory tests, including sex hormones, were within the normal range. The tumor was resected surgically under local anesthesia. The cyst had a slightly yellow wall and contained clear, watery fluid. The patient had no other medical problems and no history of other skin disease. Histopathologically, the unilocular cyst was lined with two layers of epithelium and was devoid of papillary infolding. The inner layer of the cyst was composed of cuboidal to columnar epithelial cells, most of which demonstrated prominent cilia. The outer layer consisted of polygonal cells that contained clear cytoplasm ( Fig. 1 ). No foci of squamous metaplasia were present and the cyst wall did not contain adnexal structures. The inner layer of the epithelium was positive for periodic acid–Schiff (PAS) stain, but contained no diastase‐resistant granules.

Figure Figure 1  Open in figure viewer PowerPoint Hematoxylin and eosin staining. A unilocular cyst lined with two layers of epithelium (original magnification, × 200)