Histological variety of localized lymphoid hyperplasia of the large intestine: histopathological, immunohistochemical and genotypic findings of 16 cases.

Previous reports emphasized that localized lymphoid hyperplasia (LLH) of the large intestine is usually histologically characterized by large lymphoid follicles with striking enlarged germinal centers, and a narrow surrounding mantle zone and marginal zone (MZ). To clarify the histological varieties of LLH of the large intestine, 16 such cases have been studied. The present study demonstrated histological diversity of the LLH of the large intestine including (i) reactive follicular hyperplasia (RFH) (n=8), (ii) RFH with progressive transformation of the germinal center (PTGC) (n=3), (iii) RFH with MZ hyperplasia (n=3) and (iv) RFH with PTGC and MZ hyperplasia (n=2).