Lymph node infarction in classical Hodgkin's lymphoma.

Among lymphoproliferative disorders, lymph node infarction appears to be most frequently seen in diffuse large B-cell lymphoma, followed by follicular lymphoma, with other types being rare. We experienced one such case, classical Hodgkin's lymphoma (cHL) associated with lymph node infarction, in which Reed-Sternberg (RS) cells were positive for CD15, CD30, fascin, PAX-5, p53, latent membrane protein-1 (LMP-1), Bcl-2, and EBV-encoded small non-polyadenylated RNAs. Furthermore, RS cells in the infarcted area were still positive for CD30, fascin, p53, and Bcl-2. For definitive diagnosis of nodal lymphomas including Hodgkin's lymphoma, identification of the effacement of normal nodal architecture is essential. Although this could not be evaluated in our case because of predominant reactive follicular hyperplasia with interfollicular distribution of RS cells, the presence of large cells with RS cell-related molecules together with the distorted distribution of cCD3-positive cells and CD20-positive cells led us to make a definitive diagnosis of cHL. It is, therefore, considered that immunohistochemical evaluation of the infarcted lymph node is, at least on some occasions, still informative for more accurate diagnosis of lymphoid neoplasia. Hodgkin's lymphoma should also be considered when one encounters lymph node infarction.