Kikuchi's disease: report of three cases and an overview.

We describe, to our knowledge, the first native Finnish patients with Kikuchi's histiocytic necrotizing lymphadenitis. The diagnosis was based in all cases on histopathological findings in open biopsy. The disease was first detected in Japan in 1972, but in Scandinavia, until this decade, there had been no cases reported. Our patients were young, otherwise healthy women who had cervical lymphadenopathy, fever, and fatigue as their main symptoms. In two of them, the disease was mild and subsided spontaneously within 2-6 months. One patient with more fulminant lymphadenopathy was treated with antimicrobial and antiinflammatory drugs. She became symptomless in 3 months. The cause of Kikuchi's disease is unknown. A viral or postviral hyperimmune reaction has been proposed as its etiology. Malignant lymphoma and systemic lupus erythematosus are differential diagnoses. Histopathological findings are pathognomonic and pathologists must be aware of its typical characteristics.