Post-capillary venules in the human lymph nodes draining malignant tumours.

A total of 275 regional lymph nodes from an equal number of patients with either breast, bronchial, colorectal, gastric or kidney carcinoma were histologically evaluated with special attention focused on the structure of the post-capillary venules (PVC). Three grades of PVC were differentiated on the basis of their endothelial cell morphology and the post-capillary venule score (PCV-S) was calculated for each of the nodes studied. The highest PCV-S was obtained for the control nodes followed in decreasing order by the breast carcinoma series, the renal carcinomas, the gastric carcinomas, the colorectal carcinomas and the bronchial carcinomas. The statistical significances between the PCV-S values obtained were calculated and the possible relationship between these structural changes in PCV endothelium and the T-lymphocyte recirculation was discussed.