臼後部歯肉に発生した乳頭状唾液腺腺腫類似導管内乳頭状腫瘍の1例

抄録

Sialadenoma papilliferum (SP) was first reported in 1969. The lesion is characterized by extroverted papillary hyperplasia of the mucosal epithelium and introverted hyperplasia of the ductal epithelium. In 2020 a tumor lacking exophytic growth was reported as SP-like intraductal papillary tumor (SP-IPT) by Nakaguro et al. We report a case of SP-IPT of the lower retromolar gingiva. An 84-year-old woman visited our hospital due to a mass on the left lower jaw. A mass of 15 × 11 × 6 mm was found in the alveolar part of the left lower molar, and CT imaging showed no apparent bone destruction. The tumor was removed under general anesthesia. It was partially pedunculated and well-defined, and the surface mucosa was smooth. Histopathologically, the lining epithelium in the inner layer of the tumor duct was papillary protruding toward the lumen, and no exophytic growing tumor tissue was observed. Immunohistochemistry showed positive immuno-reactions for P-63 protein and V600E mutant BRAF protein. Therefore, we diagnosed SP-IPT. There was no evidence of recurrence one year after the excision, however the patient died of heart failure one year and three months after the operation.