关键词: 肌上皮癌, 涎腺, 诊断, 免疫组织化学, 治疗

Abstract: Background and purpose: Salivary gland myoepithelial carcinoma (MC) is a rare malignant salivary gland neoplasm, and its diagnosis and treatment remain controversial. This study aimed to discuss the clinical features, pathological manifestation, immunohistochemical phenotype and therapy in order to make progress in diagnosis and treatment of salivary gland MC. Methods: The clinical data of 12 cases of salivary gland MC from Jan. 2010 to Jun. 2016 were analyzed. The average age of the 12 cases was (48.9±12.2) years. Microscopic changes were analyzed after the sections were stained with routine H-E and immunohistochemical methods. 11 cases received radical surgery only, and 2 cases received postoperative radiotherapy. One case with incomplete resection was administered with 4 cycles of docetaxel+cisplatin chemotherapy regimen (120 mg docetaxel on day 1 and 40 mg cisplatin on days 1‑3, every 28 days). Results: Seven cases occurred in parotid glands and 5 occurred in minor salivary glands. The common size of MC was between 2 and 5 centimeters. Tumors in section appeared off white or grey pink, the capsules were intact, the boundaries were unclear, and necrosis and liquescence existed. Clear cells were predominant in MC, while epithelioid, plasmacytoid, and spindle cells also existed. Cell atypia was obvious and necrosis and liquescence were shown in 4 cases. CK, S-100, EMA, SMA, calponin, p63, Vim and Ki-67 were expressed in 12, 7, 7, 4, 8, 11, 5 and 9 cases, respectively. Ki-67 labelling index was 2%～40%, and 15% was the average. The follow-up time was 2-78 months. Local recurrence and metastasis were not detected in 10 cases who underwent extended resection, and 1 case died of renal myoepithelial carcinoma 5 months after operation. One case died 3 months after chemotherapy. Conclusion: The histological changes of myoepithelial carcinoma cells are diverse. Pathological methods and the immunohistochemical examination of CK, p63, Ki-67, S-100, Vim, calponin, EMA and SMA are helpful for improving the diagnosis rate. Surgery with tumour-free margins is the main treatment for myoepithelial carcinoma. Neck dissection is not necessary for the cases without local lymphatic metastasis.

Key words: Myoepithelial carcinoma, Salivary gland, Diagnosis, Immunohistochemistry, Treatment