The basement membranes may be multiplied. Hodgkin's is very rare . Four Main Histological Features of PCL 1. Affinity of the neoplastic cells for blood vessels and their surroundings. There is diffuse infiltration of the parenchyma for some distance beyond the grossly evident tumor.
Tumor invades along perivascular spaces with perivascular cuffing.
The lymphocytes laminate beneath the endothelium, and enter the media and adventitia. Association of reactive lymphocytes. Perivascular deposition of reticulin. Predictable expression of immunohistochemical markers. The same classification as systemic non-Hodgkin's lymphoma is used.