Sedassari Bruno T, da Silva Lascane Nelise A, Tobouti Priscila L, Pigatti Fernanda M, Franco Maria I F, de Sousa Suzana C O M
From the Oral Pathology Department (BTS, NADSL, PLT, FMP, COMDS); Pathology Department, School of dentistry/University of São Paulo (MIFF), São Paulo, Brazil.
Medicine (Baltimore). 2014 Dec;93(27):e146. doi: 10.1097/MD.0000000000000146.
Carcinoma ex pleomorphic adenoma (CXPA) is an unusual epithelial malignancy that develops from a primary or recurrent pleomorphic adenoma (PA), the most common tumor of salivary glands, and constitutes about 11.5% of all carcinomas that affect these glands. Intraoral minor salivary glands and seromucous glands of the oropharynx are uncommon locations of CXPA. On histopathological examination, the tumor comprises a wide morphological spectrum with a variable proportion between the benign and malignant components with the latter often predominating and overlapping the PA, which may cause misdiagnosis. Here, we report a case of palatal minor salivary gland CXPA composed of invasive micropapillary salivary duct carcinoma and adenoid cystic carcinoma components with multiple nodal metastases in a 74-year-old woman. Neoplastic cells showed heterogeneous immunohistochemical profile with both luminal and myoepithelial differentiation. The invasive micropapillary salivary duct carcinoma component demonstrated overexpression of the oncoprotein human epidermal growth factor receptor-2. This feature should be considered and evaluated as a possible target for adjuvant therapy in case of metastatic disease.
多形性腺瘤恶变（CXPA）是一种罕见的上皮性恶性肿瘤，由原发性或复发性多形性腺瘤（PA）发展而来，PA是唾液腺最常见的肿瘤，CXPA约占所有累及这些腺体的癌的11.5%。口腔内小唾液腺和口咽的浆液黏液腺是CXPA不常见的发病部位。在组织病理学检查中，肿瘤具有广泛的形态学谱，良性和恶性成分的比例各不相同，后者通常占主导并与PA重叠，这可能导致误诊。在此，我们报告一例74岁女性腭部小唾液腺CXPA，由浸润性微乳头状唾液腺导管癌和腺样囊性癌成分组成，并伴有多处淋巴结转移。肿瘤细胞显示出具有管腔和肌上皮分化的异质性免疫组化特征。浸润性微乳头状唾液腺导管癌成分显示癌蛋白人表皮生长因子受体-2过表达。在转移性疾病的情况下，这一特征应被视为并评估为辅助治疗的可能靶点。
