Sebaceous Carcinomas: A Clinicopathological Comparison of Ocular and Extraocular Variants.

Sebaceous carcinomas (SC) are rare tumors and are currently classified into ocular and extraocular variants. Both variants of SC have very different clinical behavior and different histomorphologic appearance; however, published data are confounding as literature describes prognosis of both variants is similar or even that extraocular variants are more aggressive. In this study we evaluated the clinical and the histopathology of ocular and extraocular SC to confirm the difference between them. We performed a retrospective review of SC in which we studied the clinical and histomorphologic features of 106 cases, including 39 cases of ocular SC and 67 cases of extraocular SC. Only 2/67 cases of extraocular SC had multiple recurrences and none of them metastasized as opposed to our cases of ocular SC wherein 21/39 cases were locally aggressive with multiple recurrences and 5 cases metastasized. Histologically, both neoplasms showed major distinct morphologic features including poor differentiation in cases of ocular SC and well-differentiated tumors in the extraocular anatomic sites. To the best of our knowledge, this is the first case series of SC that compares the clinicopathologic features of ocular and extraocular variants. Awareness of such discrepancy is key to understand this disease and to possibly diagnose and manage these patients accordingly.