Relationship between lymph node metastasis and pathologic features of invasive micropapillary carcinoma of breast / 中华病理学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the relationship between lymph node metastasis and pathologic features of invasive micropapillary carcinoma (IMPC) of the breast.</p><p><b>METHODS</b>Histopathologic features and status of lymph node metastasis of fifty-one cases of IMPC were studied by microscopic examination, immunohistochemical staining (VEGF-C and VEGFR-3) and analysis of lymphatic vessel density.</p><p><b>RESULTS</b>(1) The number of positive lymph nodes in histologic grade II/III IMPCs was significantly higher (mean 12.5) than that in histologic grade I tumors (mean 4.0). (2) The incidence of nodal metastases in IMPCs with lymphocyte infiltration (+)/(++) was significantly higher (27/28, 96.4%) than that in tumors with no or minimal lymphocyte infiltration (-)/(+/-) (14/23, 60.9%), and the number of positive nodes was also higher (mean 14.4) in tumors with lymphocyte infiltration compared with those without (mean 4.6). (3) In IMPCs with histologic grade II/III, the expression of VEGF-C was significantly higher than that of histologic grade I tumors (P = 0.03). VEGF-C expression was in positive correlation with lymph node metastasis (P = 0.006) and lymphatic vessel density (P = 0.009). Lymph node metastasis was also correlated with lymphatic vessel density (P = 0.007). (4) The percentage of IMPC component in the tumor did not correlate with nodal metastasis. The metastatic foci in lymph node were all IMPC or mainly IMPC. (5) Fourteen of twenty-eight cases (14/28, 50%) of IMPC containing ductal carcinoma in-situ (DCIS) were DCIS of micropapillary type.</p><p><b>CONCLUSIONS</b>The histologic grade, lymphatic vessel density and lymphocyte infiltration are key histological features that are correlated with lymph node metastasis of IMPC. The expression of VEGF-C and VEGFR-3 may play an important role in the development of lymph node metastasis of IMPC. Micropapillary type DCIS may be the early stage of IMPC.</p>