Four Cases of Malignant Sebaceous Tumors of the Skin

—Histogenetical Consideration and Review of the Literatures in Japan—

Abstract

Four cases of two types of malignant sebaceous tumors originating in the skin were presented. According to the recent classification of Rulon and Helwig, the two cases (54-year-old and 67-year-old female) were diagnosed as basal cell carcinoma with sebaceous differentiation, and the others (53-year-old male and 67-year-old female) were sebaceous carcinoma. All tumors showed raised-up lesions on the skin of the face and scalp, and measured from 1.0 to 3.0 cm in diameter. Hitologically, the lesions of basal cell carcinoma with sebaceous differentiation were composed chiefly of foam cells and immature cells possessing basophilic cytoplasm, and that of sebaceous carcinoma chiefly of foam cells and immature cells with acidophilic cytoplasm. Based on the basophilism of cytoplasm, both types of tumors can be differentiated. Reviewing several methods of classification and the literatures in Japan, the histogenesis and clinicopathological nature of sebaceous tumors were discussed.