Fig. 1

Lymph node biopsy showing features of Castleman disease of hyaline-vascular type. Numerous small follicular structures, follicular dendritic type cells, and blood vessels, some with hyaline walls in the centers of the follicles, can be seen. Concentric layers of lymphocytes around the follicles corresponding to the mantle zone, as well as small lymphocytes among the venules with occasional reactive follicles, are also shown