Mast cell changes and tumour dissemination in human breast carcinoma.

In breast carcinoma metachromasia on staining the primary tumour with toluidine blue is related to mast cell changes and an infiltrative as opposed to an expansive growth form. In 73 patients the presence of metachromasia in the zone of host-tumour interaction, just beyond the edge of the tumour cells, was associated with poor short-term survival, giving greater discrimination than, for example, axillary nodal status or histological grade. 12 of 19 patients with metachromasia in this zone died within 5 years of operation. This indicates that the reaction is not only related to local infiltrative growth, but may also reflect the tumour potential for metastatic spread. In the absence of metachromasia in this zone death occurred mainly in patients with poorly differentiated tumours. The possible mechanisms involved are discussed. It is stressed that stromal metachromasia is not tumour specific, but that in certain areas, under defined circumstances, it may give information of both prognostic and biological interest.