Oncocytic carcinoma arising in submandibular gland with immunohistochemical observations and review of the literature.

We report a case of oncocytic carcinoma arising in submandibular gland. The tumour occurred in the left submandibular gland of an 82-year-old Japanese man. Histologically, the tumour was mostly composed of large cells with eosinophilic granules in the cytoplasm and they were arranged in the solid sheets, islands with duct-like structure and cords. The tumour cells had aggressively invaded muscles and perineural tissues, and cervical lymphatic metastasis was frequently observed. Histochemically, the tumour cells were strongly positive for phosphotungstic acid-hematoxylin (PTAH) stain, and we diagnosed this malignant tumour as oncocytic carcinoma. Immunohistochemically, the tumour cells reacted positively for cytokeratin 7, 8, 19, epithelial membrane antigen (EMA), alpha-1-antichymotrypsin and carcinoembryonic antigen (CEA), but negative for cytokeratin 13, 14, smooth muscle actin (HHF35) and S-100 protein (S-100). Tumour was diagnosed as oncocytic carcinoma in submandibular gland. Its characteristics are discussed in term of its histopathological and immunohistochemical features.