CALCIFYING EPITHELIOMA OF MALHERBE

Abstract

THE DIAGNOSIS of calcifying epithelioma of Malherbe is only rarely made on clinical grounds but is, as a rule, easily made by histologic examination. Only one other tumor, calcified epidermal cyst, resembles calcifying epithelioma in its microscopic appearance. On the basis of 15 cases the clinical and histologic characteristics of calcifying epithelioma of Malherbe will be described. Its histologic differentiation from calcified epidermal cyst will be discussed. Furthermore, the histogenesis of calcifying epithelioma will be commented on. The theory that calcifying epithelioma develops from immature hair matrix cells is supported. CLINICAL DATA Incidence.— Calcifying epithelioma is not particularly rare. Ch'in¹ found 10 such tumors among 22,000 routine surgical specimens, while Highman and Ogden² found 11 tumors among 24,185 specimens. At the pathology laboratory of the Massachusetts General Hospital 29,488 surgical specimens were received from Jan. 1, 1945 to Jan. 31, 1948. Fifteen were diagnosed as calcifying epithelioma of