Follicular Hyperplasia with Castleman-Like Changes Suspicious for Follicular Lymphoma

Lessons From the Friday Unknowns

Histologic sections show multiple lymph nodes in which there are numerous follicles, most of which are small, but with some variation in size.

The follicles are abnormally distributed in the cortex and medulla of the lymph node, and a few follicles are present in perinodal adipose tissue.

Most of the follicles also show Castleman-like changes with regression of germinal centers, decreased germinal center B-cells, increased follicular dendritic cells and some follicles show expanded mantle zones with onion skin-like changes.

Radial arterioles are prominent and show some sclerosis of their walls, but well-developed hyaline vascular lesions are not identified.