乳腺基底细胞样癌的临床病理观察

Clinicopathological characteristics of breast basal-like carcinoma

目的探讨乳腺基底细胞样癌(basal-like carcinoma,BLC))的临床病理特征、免疫表型特点及预后。方法收集乳腺BLC12例,总结其临床资料、大体及组织病理学特征,并进行免疫组化EnVision法染色。选用的抗体包括CK5/6、vimentin、CK8、ER、PR及c-erbB-2等。结果本组患者均为女性,发病平均年龄40.4岁。12例乳腺BLC均为组织学Ⅲ级。肿瘤表现为无腺管的富于细胞的实性结构,周围有较少的纤维结缔组织间隔;大多数表现为推进式生长方式,周围有大量淋巴细胞浸润;排列呈实性巢状、片状、团块状及粗大带状结构伴有片状地图样坏死,肿瘤中央可出现无细胞结构的纤维瘢痕。肿瘤细胞胞质少呈合体状,核为圆形、卵圆形,胞核胞质比例高,核分裂象活跃。12例乳腺BLC的免疫表型均为ER、PR及c-erbB-2阴性,而CK5/6、CK8及vimentin阳性。结论乳腺BLC是一种新的乳腺癌类型,具有独特的免疫组化特征、组织形态学特点及生物学特性,应作为一种独立的乳腺癌亚型加以认识。

Purpose To investigate the clinicopathological features, immunophenotype and prognosis of breast basal-like carcinoma （BLC）. Methods 12 cases of breast BLC were analyzed with respect to clinical information and pathological features. Immunohisto- chemical study （EnVision method, for cytokeratin 5/6, cytokeratin 8, vimentin, estrogen receptor, progesterone receptor, c-erbB-2） was performed. Results All the patients were females with a mean age of 40. 4 years. Histologically, the tumors were grade 3 ductal carcinoma. The tumors showed solid architecture with no tubule formation and a high density of tumor cells with scant intervening stroma between tumor cells. The majority of tumors showed a pushing growth pattern and had some degree of a stromal lymphocytic infiltrate at the tumor edge. The tumor cells were arranged in solid-nests, sheets, cords and regions of ribbon-like architecture with associated central geographic necrosis and showed a central acellular fibrotic zone. The tumor cells contained scant cytoplasm and round to oval nuclei producing a high nuclear/cytoplasmic ratio and showed syncytial growth. A high mitotic rate was identified in all tumors. The consistent immunophenotype seen in the basal-like tumors was negativity for ER, PR and e-erbB-2, and positivity for cytokeratin 5/6, vimentin and cytokeratin 8. Conclusions Breast BLC is a new subtype of breast carcinoma with unique immunophenotype, distinctive morphological features and prognosis. Conventional light microscopy usually permits a correct diagnosis.