Kukuchi's disease was first reported in 1972 as lymphadenitis with focal proliferation of reticulum cells accompanying nuclear debris. The disease demonstrates destinctive histological features, such as focal or partial involvement of the lymph nodes with accumulation of tranformed lymphocytes, immunoblasts, plasmacytoid monocytes, histiocytes with or without phagocytosis, and apoptotic bodies in the paracortex or cortex. No infiltrates of neutrophils, eosinophils and plasma cells are found in the affected foci. Large areas of necrosis and an appearance of foamy histiocytes are recognized occasionally. We examined over 400 cases. The patients represent characteristic clinical features such as an appearance in adolescence, preference to female, lymphadenopathy in the neck, leucopenia with a few atypical lymphocytes, fever over 38ﾟC, skin rashes, spontaneous regression within several months, and rare recurrences.
The lymphoid cells in the affected areas are composed of CD4 or CD8. The CD8 positive cells reveal a high proliferation activity and apoptotic changes are found mainly in CD8 positive cells. Both granzime B and perforin pathway, and fas and fas-ligands pathway are found for apoptotic process. Many of CD4 positive cells are plasmacytoid monocytes. The same histological features are noticed in other organs, such as the skin and bone marrow.
Frequent appearance of tubuloreticular structures in the proliferating cells, an elevation of 2'5' oligoadenylate synthetase in the early stage of the disease suggest viral origin of the disease, but no definite evidence of viral origin has been confirmed.
Many cases have been reported mainly in Asia. HLA typing of the cases reeals relatively high population of DQA-1-0103,0302, DQB1-0601 and high linkage equilibrium of DQA-10103-DQB1-0601, which are high in Japanese.