Maiorano Eugenio, Mazzarol Giovanni M, Pruneri Giancarlo, Mastropasqua Mauro G, Zurrida Stefano, Orvieto Enrico, Viale Giuseppe
Department of Pathological Anatomy and Genetics, University of Bari, Bari, Italy.
Am J Surg Pathol. 2003 Apr;27(4):513-8. doi: 10.1097/00000478-200304000-00012.
Epithelial inclusions representing ectopic breast tissue are uncommonly seen in axillary lymph nodes. The extensive histopathologic examination of axillary sentinel lymph nodes of patients with breast carcinoma may increase the chances to encounter tiny foci of ectopic breast tissue, which may be misinterpreted as (micro)metastatic disease and lead to unwarranted completion of axillary dissection and to inaccurate staging and improper adjuvant treatments for the patients. Here we report on seven cases of ectopic breast tissue in axillary sentinel lymph nodes. In three cases there were coexistent micrometastases, and in the remaining cases the ectopic tissue was not associated with metastatic disease. The ectopic breast tissue showed remarkably varied morphologic features, including apocrine metaplasia and proliferative changes indistinguishable from those occurring in sclerosing adenosis and florid epithelial hyperplasia of the breast. A peripheral layer of myoepithelial cells was consistently detected in the ectopic glands and ducts. Besides awareness and purely morphologic criteria, a false-positive identification of these inclusions as metastatic carcinoma may be avoided by the use of immunohistochemical reactions for the localization of specific markers of the myoepithelial cell component, which is associated with the ectopic breast tissue.
代表异位乳腺组织的上皮性包涵体在腋窝淋巴结中并不常见。对乳腺癌患者腋窝前哨淋巴结进行广泛的组织病理学检查，可能会增加发现微小异位乳腺组织病灶的机会，这些病灶可能被误诊为（微）转移瘤，从而导致不必要的腋窝淋巴结清扫，并导致患者分期不准确和辅助治疗不当。在此，我们报告7例腋窝前哨淋巴结中出现异位乳腺组织的病例。其中3例同时存在微转移，其余病例的异位组织与转移瘤无关。异位乳腺组织表现出显著多样的形态学特征，包括大汗腺化生以及与乳腺硬化性腺病和旺炽性上皮增生中所见难以区分的增殖性改变。在异位的腺管和导管中始终能检测到一层外周肌上皮细胞。除了提高认识和依靠纯粹的形态学标准外，通过使用免疫组化反应来定位与异位乳腺组织相关的肌上皮细胞成分的特异性标志物，可以避免将这些包涵体误判为转移癌。
