Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, MD 21231.
Hum Pathol. 2013 Oct;44(10):1982-8. doi: 10.1016/j.humpath.2013.03.017. Epub 2013 Jun 14.
Mammary analogue secretory carcinoma is a recently described salivary gland neoplasm defined by ETV6-NTRK3 gene fusion. Mammary analogue secretory carcinoma's morphology is not entirely specific and overlaps with other salivary gland tumors. Documenting ETV6 rearrangement is confirmatory, but most laboratories are not equipped to perform this test. As mammary analogue secretory carcinomas are positive for mammaglobin, immunohistochemistry could potentially replace molecular testing as a confirmatory test, but the specificity of mammaglobin has not been evaluated across a large and diverse group of salivary gland tumors. One hundred thirty-one salivary gland neoplasms were evaluated by routine microscopy, mammaglobin immunohistochemistry, and ETV6 break-apart fluorescent in situ hybridization. The cases included 15 mammary analogue secretory carcinomas, 44 adenoid cystic carcinomas, 33 pleomorphic adenomas, 18 mucoepidermoid carcinomas, 10 acinic cell carcinomas, 4 adenocarcinomas not otherwise specified, 3 polymorphous low-grade adenocarcinomas, 3 salivary duct carcinomas, and 1 low-grade cribriform cystadenocarcinoma. All 15 mammary analogue secretory carcinomas harbored the ETV6 translocation and were strongly mammaglobin positive. None of the 116 other tumors carried the ETV6 translocation; however, mammaglobin staining was present in 1 (100%) of 1 low-grade cribriform cystadenocarcinoma, 2 (67%) of 3 polymorphous low-grade adenocarcinomas, 2 (67%) of 3 salivary duct carcinomas, 2 (11%) of 18 mucoepidermoid carcinomas, and 2 (6%) of 33 pleomorphic adenomas. Mammaglobin is highly sensitive for mammary analogue secretory carcinoma, but immunostaining can occur in a variety of tumors that do not harbor the ETV6 translocation. Strategic use of mammaglobin immunostaining has a role in the differential diagnosis of salivary gland neoplasms, but it should not be indiscriminately used as a confirmatory test for mammary analogue secretory carcinoma.
乳腺型分泌性癌是一种新近描述的唾液腺肿瘤，其特征为 ETV6-NTRK3 基因融合。乳腺型分泌性癌的形态学并非完全特异，与其他唾液腺肿瘤存在重叠。ETV6 重排的检测具有确认意义，但大多数实验室并不具备进行该检测的条件。由于乳腺型分泌性癌表达乳腺球蛋白，免疫组化检测可能可以替代分子检测作为一种确认性检测，但乳腺球蛋白的特异性尚未在一大组不同的唾液腺肿瘤中进行评估。通过常规显微镜检查、乳腺球蛋白免疫组化和 ETV6 断裂分离荧光原位杂交，对 131 例唾液腺肿瘤进行了评估。这些病例包括 15 例乳腺型分泌性癌、44 例腺样囊性癌、33 例多形性腺瘤、18 例黏液表皮样癌、10 例腺泡细胞癌、4 例非特指型腺癌、3 例多形性低度恶性腺癌、3 例唾液腺癌和 1 例低级别筛状囊腺癌。所有 15 例乳腺型分泌性癌均存在 ETV6 易位，且乳腺球蛋白染色均为强阳性。而其他 116 例肿瘤均未发生 ETV6 易位；然而，1 例（100%）低级别筛状囊腺癌、2 例（67%）多形性低度恶性腺癌、3 例（67%）唾液腺癌、2 例（11%）18 例黏液表皮样癌和 2 例（6%）33 例多形性腺瘤存在乳腺球蛋白染色。乳腺球蛋白对乳腺型分泌性癌具有高度敏感性，但免疫染色也可发生于不携带 ETV6 易位的多种肿瘤中。乳腺球蛋白免疫染色在唾液腺肿瘤的鉴别诊断中具有一定作用，但不应不加选择地将其作为乳腺型分泌性癌的确认性检测。
