Regularity Of Pathologic Changes And Pathogenesis Of Kikuchi-Fujimoto Lymphadenitis

Background / Objectives:Kikuchi-Fujimoto disease (KFD) , or histiocytic necrotizing lymphadenitis, Originally described in the Japanese literature separately by Kikuchi and Fujimoto in 1972. It is easy to misinterpret as malignant lymphoma because of its complicated characteristic of pathomorphology and the transformed lymphocyte and atypical histiocytes in the lesions of lymph nodes of KFD . The mistaken rate add up to 30%. The research were concentrated on the changes of parenchymal cells of lymph node and immune phenotype in the last decade. But less researching on whether proliferative lymphocytes have monoclonal. The etiology and pathogenesis of KFD are unknown. Several features of KFD suggest that the cause is likely to be infectious .Arguably the most commonly detected infectious agent in KFD is EBV and M.TB. In order to provide accurate diagnosis and differential diagnosis evidence we study the expresstion of antigen, TCR-r gene-rearrangment, EBV-LMP1, BCG, fragments of Mycobacterium tuberculosis and EBV-BamHIW, immunohistochemistry, touch-down PCR,PCR and N-PCR., and also observed the composing in the lesions , regularity of histopathology, the changes of vascular and the relationship of this disease with EBV and M.TB, which may offer some information in the etiology and pathogenesis of KFD. Results1. Through observing 60 cases of clinically and histopathologically diagnosed asKFD we found that approximately 95 percent cases coexist of three types of pathologic characteristic ,ie proliferative ,necrotizing and xanthomatous. About 56.6 percent cases were dominated of proliferation, necrotizing 28.4 percent, xanthomatous 5 percent. The lesions in lymph nodes of KFD were composed of transformed lymphocytes (mainly immunoblast and small lymphocyte ), atypical histiocytes and abundant nuclear debris. In all cases,the histiocytes were observed and most of them were positive for CD68, Mac387 and MPO.Immunblasts and small lymphocytes.revealed strong T-cell positivity. In the proliferative phase,Ki67 expression was strong positive.2. The lesions of vascular manifestation in KFD involved abundant blood vessels, proliferating and swelling of vascular endothelial cells, onion-peel appearance of vessels. In the lesions of necrotizing thrombosis and necrosis of vascular wall were also found, but neovascular in xanthomatous .The deposition of complement C3 were observed in vascular walls of 19 cases (31.7 percent). 3.Twelve cases were positive detected on agarose gel electrophoresis for PCR tests of TCR gamma rearrgement. Three cases showed an oligoclonal pattern in the positive cases by SSCP analysis. Nine cases showed polycolonal. 4. 10 of the 60 cases were postive in N-PCR , but of which antibody of BCG were observed in six cases. Three cases shown tuberculoid granuloma. EBV-BamHIW gene fragments and EBV-LMP1 weren't detected in the KFD. Conclution:1. Approximately 95 percent cases coexist of three types of pathologic characteristic. In order to accurate diagnostic and differential diagnosis immunohistochemistry and gene-rearranment shoud be operate simultaneously.2. There may be some relationship between KFD and auto-immue by observing the regularity in the changes of vascular in lesions.3.There may be some relationship between KFD and Mycobacterium tuberculosis, but no obvious relation with EBV infectious.