What is "pilomatricoma"

Pilomatricoma, also known as a calcifying epithelioma of Malherbe, Malherbe calcifying epithelioma, and Pilomatrixoma, is a benign skin tumor derived from the hair matrix. These neoplasms are relatively uncommon and typically occur on the scalp, face, and upper extremities. Clinically, pilomatricomas present as a subcutaneous nodule or cyst with unremarkable overlying epidermis that can range in size from 0.5-3.0 cm, but the largest reported cases was 24 cm.