Intraductal carcinoma of the retromolar trigone found with elevated serum CEA and CA19-9 levels: a case report

Abstract

ARIKAWA Sho ・ YAMAKAWA Nobuhiro ・ KIRITA Tadaaki : Intraductal carcinoma (IDC) is a rare salivary gland tumor, classified according to the 4 th WHO Classification of Head and Neck Tumors in 2017. The tumor affects the parotid gland much more frequently than the minor salivary glands. It' s often asymptomatic. We report a case of IDC of the left retromolar trigon occurring in an 81-year-old woman. She was diagnosed with high serum CEA and CA19-9 at a medical examination. Examinations of her gastrointestinal tract, lungs, and mammary glands were conducted, resulting in no abnormal findings. FDG-PET showed abnormal uptake only in the left retromolar trigon, and a painless mass was observed. A biopsy of this tumor indicated it was likely a low-grade salivary gland tumor. The tumor was completely removed, along with sufficient margins. Histological examination revealed that the lesion was composed of alveolar nests showing an expanded duct-like structure surrounded by an intact myoepithelial layer, with no evidence of infiltration. The final diagnosis was IDC. The postoperative course was uneventful and the patient' s serum CEA and CA19-9 levels decreased to within normal range. We believe that serum CEA and CA19-9 levels could be used for the diagnosis and evaluation of therapeutic effect for this tumor.: carbohydrate antigen19-9 (CA19-9) ，carcinoembryonic antigen (CEA) ，intraductal carcinoma (導管内癌) ， minor salivary gland (小唾液腺) ，tumor marker (腫瘍マーカー) 奈良県立医科大学口腔外科学講座 (主任：桐田忠昭教授)