Histiocytic necrotizing lymphadenitis (Kikuchi's disease).

Histiocytic necrotizing lymphandenitis (HNL), or Kikuchi's disease, is a newly recognized disease of unknown origin that causes cervical lymphadenitis, usually in young women. Initially described in Japan, cases of HNL are being reported in the United States and other western countries with increasing frequency. Symptoms of HNL include tender cervical adenopathy, fever, weight loss, and night sweats. Laboratory studies reveal leukopenia with relative granulocytopenia and lymphocytosis. Lymph node biopsy reveals areas with frank cellular necrosis, karyorrhexis, and absence of plasma cells. The histologic features of HNL are distinctive but can be confused with those of lymphoma. We describe two cases of HNL and present recommendations for diagnosis and treatment.