Sebaceous carcinoma of the right palate: case report and literature review.

Considering the low incidence rates of primary sebaceous carcinoma (SC) of extraorbital sites, let alone those occur in intraoral sites, clinicopathological characteristics and histogenesis are not fully understood. In the present case, a maxillary mass was presented and a low-grade malignant tumor was suspected according to the CT scans, preoperative FNA, and clinical conditions. Other carcinomas, including acinar cell carcinoma (ACC), basaloid cell carcinoma (BCC), SCC, mucoepidermoid carcinoma, and epithelial-myoepithelial carcinoma (EMC), were also considered before surgery. Due to the rare occurrence of SC and no preoperative suspects, a fresh sample was not kept. Sadly, thus cause those special stains (e.g., Oil Red O and Sudan IV) which form the primary basis for a diagnosis of SC in academic circles were missing. A comprehensive literature review identified only 10 cases of intraoral SC, of which the primary sites reported in the English literature were the buccal mucosa, mouth floor, upper labial mucosa, and tongue. Due to an absence of specific biomarkers and simulated characters, histochemistry and immunohistochemistry such as PAS, CK, EMA, p63, p53, S-100, calponin, CD117, Ki-67, a-SMA, and AR form the diagnostic standard of SC. Postoperative immunohistochemistry of our case showed S100(-), Ki-67(-), calponin(-), CD117(-), CK20(-), PAS(-), AR(+), CK(+), CK5/6(+), P53(+), P63(+), a-SMA (+). Thus the diagnosis of SC was finally made. Through discussing the findings of our case and reviewing literature, we present the histological features and discuss possible outstanding biomarkers of this neoplasm.