a solitary tumor of the scalp in elderly women that may ulcerate; microscopically resembles squamous cell carcinoma composed of glycogen-rich clear cells, but is benign. Synonym(s): proliferating tricholemmal cyst
pi·lar tumor of scalp
(pī'lăr tū'mŏr skalp) A benign but sometimes ulcerative solitary tumor of the scalp in elderly women.