Three children of meningoencephalitis with Kikuchi necrotizing lymphadenitis

Kikuchi necrotizing lymphadenitis (KNL) is a rare and benign cause of lymphadenopathy, most often cervical. The etiology of KNL remains unknown. Central nervous system (CNS) involvement, such as in meningoencephalitis, is a very rare clinical manifestation of KNL, especially in children.

A 12-year-old boy presented with unilateral cervical lymphadenopathy and fever. Histopathological findings led to the diagnosis of KNL. He revisited due to severe headache and vomiting one week later. Cerebrospinal fluid (CSF) analysis demonstrated pleocytosis (lymphocytic 57%), high protein (312 mg/dL) and low CSF/serum glucose ratio (52/121 mg/dL.) The next day, he had a seizure. Brain MRI revealed increased signal involving posterior area of both hemisphere. Another 17-year-old boy presented with headache for 7 days and behavioral and personality changes. He had a history of cervical lymphadenopathy two weeks ago. CSF analysis demonstrated lymphocytosis, high protein and low glucose ratio. MRI revealed the involvement of right cerebellum and posterior brainstem. A biopsy of one cervical lymphadenopathy demonstrated the findings of KNL. A 15-year-old girl presented with fever, headache, and cervical pain lasting 10 days. CSF analysis demonstrated pleocytosis (lymphocytic 95%), high protein and low CSF/serum glucose ratio. Histopathological findings of lymph node were suggestive of KNL. Above three patients were undertaken the steroid therapy and recovered fully without neurological dysfunction.

Recognition of CNS involvement in KNL may help evaluate the patients of acute meningitis/encephalitis with regional lymphadenopathy, thereby avoiding unnecessary treatment.