A Case of Primary Submandibular Gland Oncocytic Carcinoma

Primary submandibular gland oncocytic carcinoma is a rare pathology, with only 10 cases being reported to date. We encountered a case of primary submandibular gland oncocytic carcinoma and report it herein. The patient was a 69-year-old man who came to our hospital with right submandibular cancer as the main complaint. Based on the results of computed tomography and magnetic resonance imaging, submandibular gland tumor was diagnosed. Preoperative cytodiagnosis suggested class III oncocytic carcinoma. Resection of the right submandibular tumor was performed along with right neck dissection. Postoperative histopathological diagnosis was oncocytic carcinoma. As of 3 years following surgery, no recurrence has been identified. 1. Introduction Oncocytes are epithelial cells with cytoplasm rich in eosinophilic granules. Oncocytoma is a cancerous proliferation of oncocytes that accounts for only 1% of all salivary gland tumors [1]. Oncocytic carcinoma is an even rarer malignancy that starts in the parotid glands in almost all cases. Only 10 cases of primary submandibular gland oncocytic carcinoma have been reported to date [2–10] (Table 1). Herein, we report a case of primary submandibular gland oncocytic carcinoma. Table 1: Reports of oncocytic carcinoma in submandibular glands. 2. Case Presentation The patient was a 69-year-old man who was examined for the main complaint of right submandibular cancer. The medical and family histories of the patient were unremarkable. Initial examination revealed a 15？mm × 10？mm hard, elastic tumor showing no mobility and an irregular margin. On computed tomography (CT) of the neck, a 20？mm × 10？mm nodular shadow with slight enhancement was observed in the right submandibular area (Figure 1). No clear indication of metastasis to cervical lymph nodes was apparent. No obvious distant metastases were observed on chest CT. Neck magnetic resonance imaging (MRI) revealed a 20？mm × 10？mm tumor with indistinct boundary and slight enhancement in the right submandibular gland, showing signal hypointensity on both T1- and T2-weighted imaging (Figure 2). Fine-needle aspiration (FNA) biopsy at this location indicated a class III lesion. The eosinophilic cytoplasm of duct epithelial cells and the presence of naked nuclei with prominent nucleoli made it difficult to rule out malignancy (Figure 3). Figure 1: Neck CT showing a 20？mm × 10？mm nodular shadow with slight enhancement in the right submandibular area. Figure 2: Neck MRI showing 20？mm × 10？mm tumor with an indistinct boundary and slight enhancement in the right submandibular gland.