Type IV collagen in Hodgkin's disease. An immunohistochemical study

A series of 50 lymph nodes affected by Hodgkin's disease (HD) and 10 further nodes exhibiting the features of reactive follicular hyperplasia (RFH) have been studied. A peroxidase-antiperoxidase (PAP) sequence for the demonstration of type IV collagen has been applied to routinely processed paraffin-embedded sections of these specimens. Blood vascular structures of all calibers were clearly demonstrated, as were lymphatic sinuses. Structures recognizable as the latter were generally lacking in HD, but the sinus structures in the cases of RFH were well defined. Blood vessels were highly active on type IV collagen staining in the interfollicular areas of reactive nodes but were relatively scanty in lymphocyte-predominant, mixed-cellularity, and lymphocyte-depleted HD. However, in the nodular sclerosing Rye subtype, blood vessels containing type IV collagen were as numerous as in RFH and could be seen within and around the cellular nodules. A similar number of type IV collagen-containing blood vessels were also apparent in the cellular variant of nodular sclerosing HD. The results are compared with those obtained on immunostaining for Factor VIII-related antigen and on binding of Ulex europaeus lectin I, and type IV collagen is considered to be the most sensitive vascular marker compared with these.