[Pilomatrixoma (Malherbe's calcifying epithelioma). Apropos of 13 cases observed in 6 years]

Thirteen pilomatrixomas were seen over a six year period. These small benign cutaneous tumors are infrequent though not exceptional and occur mainly in children (mean age six years). The tumor's hard consistency, irregular shape and frequently cephalic location (nearly 50% of cases) are suggestive. Diagnosis is established upon histological examination which demonstrates irregularly shaped clusters of basophilic epithelial cells; these develop into highly suggestive momified areas with shadow cells and secondary calcification. Attention is drawn to the presence of hemorrhagic modifications in recent tumors and telangiectasia. Pilomatrixomas must be considered as suborganoid hamartomas arising from the primary hair-matrix germ cells. The treatment is minimal surgical excision.