顎下腺に発生したoncocytomaの1例

Abstract

Oncocytoma is a benign salivary gland tumor composed predominantly of oncocyte, which are large epithelial cells with eosinophilic granular cytoplasm resulting from an accumulation of mitochondria. Oncocytoma is uncommon; most cases occur in the parotid gland. We encountered a rare case of oncocytoma of the submandibular gland. An 80-year-old man with a gradually-growing mass in the left submandibular region came to our clinic. The tumor was elastic soft and mobile, with a clear margin. He did not complain of pain. Contrast-enhanced computed tomography (CT) showed a homogenous submandibular mass of approximately 50 mm in diameter, and magnetic resonance images (MRI) indicated a high-intensity mass on T1 weighted imaging in the left submandibular region. The patient underwent surgery under general anesthesia. Pathological examination showed that the tumor cells were large with eosinophilic granular cytoplasm, and on the basis of these findings we diagnosed the tumor as an oncocytoma.No recurrence has been detected as of nine years after the operation.