Shadows and Ghosts of the Hair Matrix: Pilomatrixoma

The neoplasm, established as the “Calcifying Epithelioma of Malherbe”, were scripted as the lesions commencing from the sebaceous glands in the late 19th century (1880) by Malherbe and associates [1]. The histology comprises of the islands of epithelial cells and shadow cells, illustrated in the early 20th century (1922) [2]. “Pilomatrixoma” as a terminology was popularized in the late 20th century (1961) [3] and designated the neoplasm as a derivative of the hair matrix, thus circumventing the term “epithelioma”, which may connote a malignancy. The enzyme histochemistry and ultra-structural analysis of the lesion was also computed in the late 20th century (1966) [4], confirming that it originated from the primitive basal cells of the epidermis which differentiate towards the hair matrix.