RESUMEN
<p><b>OBJECTIVE</b>To investigate the relationship between partial reversed cell polarity (PRCP) and lymphatic tumor spread in invasive ductal carcinoma (IDC), not othervise specified (NOS).</p><p><b>METHODS</b>Immunohistochemistry (EnVision method) was used to examine the expression of epithelial membrane antigen (EMA) and the reversed cell polarity in 199 cases of IDC.</p><p><b>RESULTS</b>Of the 199 cases, including five cases with micropapillary differentiation,30 cases with PRCP and 164 cases of IDC-NOS (without micropapillary differentiation and/or PRCP), lymphovascular invasion was seen in four (4/5), 13(43.3%) and 30 cases (18.3%) respectively; nodal metastasis was seen in four (4/5), 19 (63.3%) and 56 cases (34.1%) respectively. The rates of lymphovascular invasion and nodal metastasis were significantly higher in IDC with PRCP or IMPC than IDC-NOS (P = 0.00); there was however no significant difference between IDC with PRCP and IMPC for lymphovascular invasion and nodal metastasis (P = 0.18, P = 0.64).</p><p><b>CONCLUSIONS</b>IDC with PRCP, similar to IMPC, is more likely to show lymphovascular invasion and nodal metastasis. Complete or partial reversal of cell polarity may play a significant role in lymphatic tumor spread.</p>