The routine histological investigation of axillary lymph nodes for metastatic breast cancer.

A simple method of preparing axillary nodes from breast cancer patients for routine histology is presented. It is based on appreciation of nodal anatomy and the pathophysiology of tumour growth in them. Current methods assume that the latter is a random process, but this is not so. It has long been known that tumour cells enter via the afferent lymphatics. They may also exit by the efferent. It has not been generally realized that these vessels enter/leave the node in the same plane of section, or that a section in this plane, a hilar section, is theoretically the one of choice for the identification of tumour cells in the node. It is shown here that use of hilar sections alone allows the identification of tumour-free and tumour-bearing nodes, as well as the tumour status of the efferent vessels, with considerable certainty. The use of random sections, in contrast, carries a high risk of false negative reporting.