Angiofollicular lymphoid hyperplasia (Castleman's disease) in two mice treated with polyoma virus or urethane

Localized angiofollicular hyperplasia, otherwise known as Castleman's disease, is described in the lymph nodes of 2 mice of different strains, one inoculated with polyoma virus at birth and the other given urethane within 24 hr of birth. A plasma cell component in the lesion, suggestive of bone marrow stem cell involvement, was present in the mouse treated with polyoma virus but absent in the mouse given intraperitoneal urethane. Dysregulated interleukin 6 has recently been reported to produce the systemic variety of angiofollicular hyperplasia in mice, but the role of this cytokine in the localized variety described in this report is not known. This lesion appears to be rare in mice, but when present it could easily be missed or overlooked because the typical layering of follicle cells and the relatively large germinal centers seen in humans do not appear prominent in mice. Although there is, obviously, no proof of a causal relationship between the lesion and polyoma virus or urethane, it is suggested that this lesion be searched for in order to estimate its frequency and possible etiologic associations.