MYOEPITHELIAL SWEAT GLAND TUMOR: MYOEPITHELIOMA

ECCRINE and apocrine sweat glands possess tubular lumens lined by two layers of cells. In their secretory portion the inner layer is composed of secretory cells and the outer layer of myoepithelial cells Tumors affecting the secretory portion of sweat glands, therefore, contain, as a rule, both secretory and myoepithelial cells. In most of these tumors the myoepithelial cells are far less numerous than the secretory cells. There exists, however, a group of benign sweat gland tumors in which the myoepithelial cells represent the majority of tumor elements. These tumors present histologic characteristics which make their recognition as a separate type of sweat gland tumor desirable. The term myoepithelioma is suggested as designation for these tumors. Descriptions of 12 cases of tumor of this type were found in the literature. Three additional cases were observed at the Massachusetts General Hospital. These 15 cases of tumor will be described in this