Reversal of glandular polarity in the lymphovascular compartment of breast cancer

Abstract

Aim: To investigate the polarity of breast invasive ductal carcinoma cells by comparing the polarity of the tumour located within lymphovascular spaces with that located in the extravascular compartment.

Methods: An immunohistochemical study identifying the apical HMFG-1, basolateral AUA-1, and basal laminin polarity markers of 11 cases of invasive ductal carcinoma (grades 1 or 2) metastatic to lymph nodes, all of which contained areas of tumour within and outside of lymphovascular spaces.

Results: Only one of 11 tumours had a focus of apparent reversed glandular polarity in the larger extravascular tumour compartment (with AUA-1 present internally and HMFG-1 expressed externally on tumour clumps), but six of the 11 tumours showed reversed glandular polarity (either with AUA-1, or HMFG-1, or both) within the very much smaller lymphovascular space tumour compartment. Laminin was not identified in association with lymphovascular tumour.

Conclusions: Reversed glandular polarity in invasive ductal breast carcinomas was identified and was significantly more frequent within vessels than outside of them. Reversal of tumour glandular polarity within lymphovascular spaces allows direct interaction between apical domain-type molecules-which are then aberrantly expressed on the external surface of tumour clumps-and lymphovascular endothelium. Such interactions may affect the establishment of metastatic disease.

Figure 1

(A) Haematoxylin and eosin stain showing nodal metastatic ductal carcinoma of the breast within both the extravascular and lymphovascular compartments of the lymph node. (B) Immunohistochemical staining of lymphovascular tumour with AUA-1 showing a luminal pattern—that is, reversal of polarity. (C) Immunohistochemical staining of lymphovascular tumour with HMFG-1 showing peripheral staining—that is, reversal of polarity. (D) Immunohistochemical staining of lymphovascular tumour with anti-laminin showing an absence of reactivity. (E) Immunohistochemical staining with anti-CD31 showing decreased staining of the endothelium associated with the tumour compared with uniform staining of endothelial cells in an adjacent vessel with no tumour.