Infundibulocystic basal cell carcinoma.
We report on a 72-year-old male patient with a solitary, dome-shaped tumor on the preauricular region. Histologically, it showed an intradermal basaloid cell tumor composed of many anastomosing epithelial cords. There were multiple infundibular cystic structures containing corneocytes lined by follicular infundibular epithelium and bud-like structures simulating the follicular germs throughout the neoplasm. Follicular bulbs and papillae were absent within the tumor. The stroma was scant and not highly fibroplastic. The tumor was diagnosed as infundibulocystic basal cell carcinoma, a recently described, uncommon variant of basal cell carcinoma.