目的 探讨乳腺浸润性微乳头状癌（IMPC）的病理学特征及其与淋巴结转移的关系。方法 回顾性分析61例IMPC患者的病理学资料，分析肿瘤T分期（肿瘤大小）、IMPC成分比例、间质淋巴细胞浸润等因素与淋巴结转移的关系。结果 IMPC淋巴管浸润率为73.8%（45/61），淋巴结转移率为75.4%（46/61）。不同T分期患者的淋巴结转移率比较差异无统计学意义（P＞0.05）；肿瘤组织中不同IMPC成分比例患者的淋巴结转移率和淋巴结转移个数比较，差异也无统计学意义（均P＞0.05）；但IMPC间质淋巴细胞浸润阴性患者的淋巴结转移率明显低于间质淋巴细胞浸润阳性者（54.2% vs 62.2%）（P＜0.05）。淋巴结转移灶为纯IMPC成分或以IMPC成分为主（39/43，90.7%）。结论 淋巴管侵袭和区域淋巴结转移是IMPC的生物学特征；IMPC的生物学行为并不取决于肿瘤的大小及肿瘤中IMPC成分的多少，而可能与IMPC成分本身的性质有关。

Objective To investigate the clinicopathologic features of invasive micropapillary carcinoma (IMPC) of breast, and explore their relationship with lymph node metastasis. Methods The clinical and pathologic features of 61 cases of IMPC of breast were retrospectively analysed, and the relationship between lymph node metastasis and factors such as T staging (tumor size), proportion of components and interstitial lymphocytic infiltration was explored. Results The rate of lymph vascular invasion of IMPC was 73.8%(45/61), and the rate of lymph node metastasis was 75.4%(46/61). There was no significant difference in rates of lymph node metastasis among patients with different T stages (P＞0.05). Besides, there was no significant difference in rates of lymph node metastasis and numbers of lymph node metastasis among different IMPC components in tumor tissues (P＞0.05 for both). However, the rate of lymph node metastasis of patients with IMPC and negative interstitial lymphocytic infiltration (54.2%) was significantly lower than that of patients with IMPC and positive interstitial lymphocytic infiltration (62.2%)(P＜0.05）. The metastatic foci in lymph node were all IMPC components or mainly IMPC components （39/43, 90.7%）. Conclusion Lymph vascular infiltration and regional lymph node metastasis are biological features of IMPC of breast. It is the characteristics of IMPC components instead of the tumor size or amount of IMPC components in the tumor that correlate with the biological behaviors of the tumor.