Histiocytic necrotizing lymphadenitis without granulocytic infiltration (the so called Kikuchi-Fujimoto disease).

The report describes five cases of a rare disorder--necrotizing lymphadenitis--diagnosed in Polish patients in the Department of Pathomorphology, Collegium Medicum, Jagiellonian University, Krakow, in the years 1993-2006. The disease was firstly described by Kikuchi and Fujimoto in the Oriental population of Japan in 1972 and for this reason it is called Kikuchi-Fujimoto disease (or Kikuchi lymphadenitis). Its characteristic histological picture includes necrosis without granulocytic infiltrate surrounded by plasmocytoid monocytes, histiocytes (CD68+, lysozyme+, myeloperoxidase+) and immunoblasts, sometimes with atypia, with concomitant lymphocytes, predominantly cytotoxic T CD8+. The histology together with the rare occurrence of the disease in Poland may be a considerable diagnostic challenge for a pathologist, leading to misdiagnosing the lesion as a neoplastic process (malignant lymphoma).