前舌腺由来と考えられた上皮筋上皮癌の1例

Abstract

Epithelial-myoepithelial carcinoma (EMC) is a rare salivary gland tumor characterized by doublelayered tubular structures composed of inner ductal epithelial cells and outer myoepithelial cells. Accounting for approximately 1% of all salivary gland tumors, EMC occurs primarily in the major salivary glands, particularly in the parotid gland. We report a rare case of EMC thought to have originated from the anterior lingual gland. A 68-year-old man visited our department due to awareness of a painful mass in the anterior tongue for one month. A submucosal elastic-hard mass measuring 30 x 25 x 15 mm was found in the anterior lingual region, and a 25 mm large, elastic firm, mobile lymph node was found in the right submandibular region. Contrastenhanced CT and MR images showed relatively clear lesions in the anterior lingual region, and the large lymph node showed contrast effect. FDG-PET/CT showed an accumulation in the anterior lingual region, but no significant accumulation in other areas. Biopsy results suggested adenoid cystic carcinoma. A partial tongue resection and selective right-sided cervical dissection (levels I-IV) were performed under general anesthesia. The histopathological diagnosis was EMC. The primary lesion was curatively resected, and one metastatic lymph node without extracapsular extension was found in the submandibular region (pT3N1) . The postoperative course has been uneventful and there have been no signs of recurrence four and a half years after surgery.