前舌腺由来と考えられた脱分化型上皮筋上皮癌の1例

• Published in: 日本口腔外科学会雑誌 Vol. 66; no. 9; pp. 444 - 449
• Main Authors: 粕谷, 賢志, 下山, 泰明, 関口, 眞人, 飯野, 光喜, 櫻井, 博理
• Format: Journal Article
• Language: Japanese
• Published: 社団法人 日本口腔外科学会 20.09.2020
• Subjects: 上皮筋上皮癌; 前舌腺; 脱分化
• ISSN: 0021-5163; 2186-1579
• DOI: 10.5794/jjoms.66.444

Epithelial myoepithelial carcinoma (EMC) is a rare malignant tumor accounting for approximately 4.1% of all salivary gland malignant tumors arising mainly in the parotid gland. We report an extremely rare case of EMC with high grade transformation originating from the anterior tongue gland.　The patient was a 66-year-old man. On clinical examination, a 50 × 35 mm elastic, hard mass was found in the tongue tip on the left side. CT and MRI showed a clear boundary tumor mass with a necrotic or bleeding region. After incisional biopsy, the mass was diagnosed as EMC. Partial glossectomy was performed under general anesthesia. Histologically, the tumor had two distinct carcinomatous components. One component showed the features of EMC, and the other showed high-grade transformation features. The Ki-67 labelling index of the EMC component was 3%, and that of the high-grade transformation component was 50%. The final histological diagnosis was EMC with high grade transformation.　Six months postoperatively, he was hospitalized because of ileus caused by metastatic peritoneal dissemination of EMC and died of multiple organ failure.