Reactive lymphoid hyperplasia of the liver characterized by an angiofollicular pattern mimicking Castleman's disease.

A case of reactive lymphoid hyperplasia of the liver exhibiting a characteristic angiofoillcular pattern is reported. A hepatic nodular lesion was discovered by abdominal echography during clinical follow-up of abnormal liver function tests. It was diagnosed as hepatocellular carcinoma because of Its hypervascularity when observed by angiography, and surgically resected. Grossly, the lesion was well-demarcated and measured 2 cm In diameter. Microscopycally, the nodule was composed of lymph follicies with germinal centers, and the hyalinized Inter-follicular space contained abundant hyalinized vasculature and plasma cells. The surrounding liver tissue exhibited chronic Inflammation with some pecullar angiofolllcular structures mimicking Castleman's disease. An Immunohistoehemical study revealed that the angiofoillcular structure had the same characteristics as a lymph follicle with a general center, and that the plasma cells proliferating in the inter-follicular space had polyclonal Immunophenotypes. These histological and immunohistochemical findings Indicated that the angiofoillcular structure observed was a kind of reactive lymph follicle, and that this hepatic lesion was reactive lymphoid hyperplasla rather than Castleman's disease or an inflammatory pseudotumor.