High endothelial venules in B-cell non-Hodgkin malignant lymphomas.

The number of high endothelial venules (HEVs) per unit area was determined in 55 B-cell non-Hodgkin malignant lymphomas (nHMLs) classified according to the Kiel classification. The number of HEVs per unit area was significantly different between low- and high-grade B-cell nHMLs. In the low-grade group, a large number of HEVs with preserved structure were present, whereas in high-grade tumours the HEVs appeared damaged. The present findings support the previous observation attributing prognostic relevance to lymphocyte recirculation in nHMLs.