Oncocytic Carcinoma of the Submandibular Gland: A Case Report

Oncocytic carcinoma (OC) of the submandibular gland is extremely rare. A 76-year-old man complained of a painless tumor of the right neck. Ultrasonography demonstrated swelling in the lymph nodes of the neck, and fine-needle aspiration cytology of a node showed metastatic carcinoma with oncocytic features. Radical surgery revealed infiltrating carcinoma of the right submandibular gland with lymph node metastases (19/23). Tumor cells showed less atypia and had abundant eosinophilic cytoplasm, which stained deep blue with phosphotungstic acid-hematoxylin stain. The cells were immunohistochemically positive for cytokeratin 7 but negative for p63 and SOX10. We diagnosed the tumor as OC. Chemoradiotherapy was performed after surgery. The patient showed no sign of recurrence until 42 months after the operation, when lymph node swelling was detected in the mediastinum by computed tomography scanning. With no further treatment, the patient is alive with lymph node swellings in the mediastinum and pulmonary hilum 80 months after surgery.