Aydın Salih, Taskin Umit, Ozdamar Kadir, Yücebas Kadir, Sar Mehmet, Oktay Mehmet Faruk, Tetikkurt Umit Seza
Department of Otolaryngology, Bağcılar Education and Research Hospital, Istanbul, Turkey.
Department of Pathology, Bağcılar Education and Research Hospital, Istanbul, Turkey.
Case Rep Otolaryngol. 2014;2014:629054. doi: 10.1155/2014/629054. Epub 2014 Sep 9.
Dedifferentiation is defined as high-grade malignant tumor development out of a low-grade malignant tumor. We present an adenocarcinoma tumor of the parotid gland that was dedifferentiated from a low-grade epithelial-myoepithelial carcinoma and was followed up for 3 years. Our patient, a 46-year-old female, presented with a left parotid mass of 20-year duration. Histopathologic results showed that there was only one area of typical epithelial-myoepithelial carcinoma, with foci of poorly differentiated adenocarcinoma (not otherwise specified; NOS) and clear cytoplasm in the parotid gland. Immunohistochemical staining results showed SMA (+), P63 (+), CK8 (+), and S100 (+) on epithelial cells. A review of the literature revealed 22 previously reported cases of dedifferentiated epithelial-myoepithelial carcinoma. In these cases, the malignant tumors that dedifferentiated from epithelial-myoepithelial carcinoma were adenoid cystic carcinoma, actinic cell carcinoma, polymorphous low-grade adenocarcinoma, mucoepidermoid carcinoma, and intraductal carcinoma. In our case, the malignant tumor that dedifferentiated from the epithelial-myoepithelial carcinoma was a poorly differentiated adenocarcinoma. Histopathological results showed that metastases were not seen in the neck-dissection material. As a result, our case will make a contribution to the literature in terms of prognosis, because there are very few reported cases of dedifferentiated adenocarcinoma development arising from epithelial-myoepithelial carcinoma.
去分化被定义为低级恶性肿瘤发展为高级恶性肿瘤。我们报告一例腮腺腺癌，它由低级上皮-肌上皮癌去分化而来，并进行了3年的随访。我们的患者是一名46岁女性，左侧腮腺肿物已有20年。组织病理学结果显示，腮腺中仅存在一个典型上皮-肌上皮癌区域，伴有低分化腺癌灶（未另作说明；NOS）及透明细胞质。免疫组化染色结果显示上皮细胞SMA（+）、P63（+）、CK8（+）及S100（+）。文献回顾显示，此前已报道22例去分化上皮-肌上皮癌病例。在这些病例中，由上皮-肌上皮癌去分化而来的恶性肿瘤有腺样囊性癌、光化性细胞癌、多形性低度腺癌、黏液表皮样癌及导管内癌。在我们的病例中，由上皮-肌上皮癌去分化而来的恶性肿瘤是低分化腺癌。组织病理学结果显示，颈清扫标本未见转移。因此，我们的病例将在预后方面为文献做出贡献，因为由上皮-肌上皮癌发展而来的去分化腺癌报道病例极少。
