Sebaceous carcinoma of meibomian gland origin. The diagnostic importance of pagetoid spread of neoplastic cells.

The clinical and pathologic features of four sebaceous carcinomas primary located in the eyelids were studied in detail. The neoplasms occurred in four patients of ages 62 to 76 years, were often misdiagnosed at initial excision, and recurred in all four cases. Three of the four cases required orbital exenteration, and preauricular lymph node metastases developed in two. The tumors were characterized by variable histologic growth patterns and evidence of sebaceous differentiation. Pagetoid spread of the neoplastic cells in the overlying epithelium was found in all four cases. Recognition of the pagetoid growth pattern in biopsy material was essential in correctly diagnosing two of the four cases. It is one of the important features enabling sebaceous carcinoma to be distinguished from basal cell carcinomas showing sebaceous differentiation.