Kikuchi histiocytic necrotizing lymphadenitis: clinicopathological and immunohistochemical study

Clinical, morphological and immunohistochemical features of 10 cases having the lymphnodal histological pattern of Kikuchi disease were examined. Two of these were diagnosed as systemic lupus erythematosus (SLE). Morphologically, Kikuchi disease and SLE were nearly indistinguishable. Plasma cells, neutrophilic infiltration, haematoxyphilic bodies and vasculitis were not useful in differentiating the conditions. Kikuchi lymphadenitis and malignant lymphoma however could be differentiated histologically. Morphological features that exclude malignancy included: polymorphous nature of cellular infiltrate, absence of abnormal mitosis, preservation of sinusoidal pattern on intervening areas and presence of extracellular and intracellular karyorrhectic debris.