Li Yu-sang, Kaneko Mayumi, Sakamoto Danielle Giacometti, Takeshima Yukio, Inai Kouki
Department of Pathology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8551, Japan.
Breast Cancer. 2006;13(1):58-63. doi: 10.2325/jbcs.13.58.
Invasive micropapillary carcinoma (IMPC) of the breast is a special subtype of invasive ductal carcinoma (IDC), which is known to have a high potential to metastasize to the axillary lymph node. However, it is sometimes difficult to differentiate IMPC from conventional IDC showing an IMPC-like pattern due to artifact (pseudo-IMPC). In the present study, we investigated the usefulness of immunohistochemical expression of MUC1 for distinguishing IMPC from pseudo-IMPC, and analyzed several clinicopathological parameters of IMPC and pseudo-IMPC cases.
Eighty cases showing IMPC or IMPC-like pattern were selected from our surgical files of 1,240 cases of IDC. We examined the expression of MUC1, D2-40 and CD34 by immunohistochemistry.
Eighty cases were classified into 9 cases (0.7%) of pure-IMPC, 31 cases (2.5%) of mixed-IMPC, and 40 cases of pseudo-IMPC, according to the expression pattern of MUC1. In pure-IMPC cases, MUC1 expression was found at the reversed apical membrane of neoplastic cell clusters, while in pseudo-IMPC, MUC1 expression was present in the whole cytoplasmic membrane and/or cytoplasm. There were no significant differences among the three groups in patient age, tumor size and nuclear grade of neoplastic cells. However, lymphatic invasion and lymph node metastasis in the pure-IMPC or mixed-IMPC cases were higher than those in pseudo-IMPC cases with statistically significant values. Pure-IMPC has a higher recurrence rate and lower overall survival compared to pseudo-IMPC [P = 0.0165(DFS) P = 0.025(OS)].
This study demonstrated that immunohistochemistry of MUC1 is useful for the diagnosis of IMPC. The pure-IMPC cases had higher incidences of lymphatic invasion and lymph node metastasis, and also showed a poorer prognosis.
乳腺浸润性微乳头状癌(IMPC)是浸润性导管癌(IDC)的一种特殊亚型,已知其具有较高的腋窝淋巴结转移潜能。然而,由于人为因素(假性IMPC),有时难以将IMPC与表现为IMPC样模式的传统IDC区分开来。在本研究中,我们调查了MUC1免疫组化表达在区分IMPC与假性IMPC中的作用,并分析了IMPC和假性IMPC病例的几个临床病理参数。
从我们1240例IDC手术档案中选取80例表现为IMPC或IMPC样模式的病例。我们通过免疫组化检测了MUC1、D2-40和CD34的表达。
根据MUC1的表达模式,80例病例分为9例(0.7%)纯IMPC、31例(2.5%)混合IMPC和40例假性IMPC。在纯IMPC病例中,MUC1表达见于肿瘤细胞簇的反转顶端膜,而在假性IMPC中,MUC1表达见于整个细胞质膜和/或细胞质。三组患者在年龄、肿瘤大小和肿瘤细胞核分级方面无显著差异。然而,纯IMPC或混合IMPC病例中的淋巴血管浸润和淋巴结转移高于假性IMPC病例,差异具有统计学意义。与假性IMPC相比,纯IMPC的复发率更高,总生存率更低[P = 0.0165(无病生存期),P = 0.025(总生存期)]。
本研究表明,MUC1免疫组化对IMPC的诊断有用。纯IMPC病例的淋巴血管浸润和淋巴结转移发生率更高,预后也更差。