[Necrotizing lymphadenitis presenting as mesenteric lymphadenopathy].

A 15-year-old girl was admitted to our hospital because of fever, diarrhea, and right lower abdominal pain on November 11, 1997. Computed tomographic and ultrasound studies of the abdomen disclosed enlarged mesenteric lymph nodes. Hematologic and serologic findings included WBC 3000/microliter, LDH 550 IU/l, IFN-gamma 264 pg/ml, IL-6 9.74 pg/ml, sIL-2R 781 U/ml, and ferritin 720 ng/ml. Although the patient was treated with antibiotics, high fever and abdominal pain persisted with progressive anemia and leucocytopenia (1800/microliter). Bone marrow aspiration specimens revealed an increase of histiocytes with phagocytosis. Appendectomy and lymphadenectomy were performed on November 21. A lymph node specimen showed necrosis with infiltration by large mononuclear cells. The resected appendix revealed reactive lymphoid hyperplasia. Based on these findings, a diagnosis of necrotizing lymphadenitis (NL) was made. The postoperative course was satisfactory and systemic symptoms resolved gradually without specific treatment. However, high fever and abdominal pain recurred with right cervical lymph node swelling on December 15. The patient's general condition improved after treatment with prednisolone. In NL, lymphadenopathy is usually observed in the cervical region, and the involvement of intra-abdominal lymph nodes is quite rare. Our findings indicated the possibility that IFN-gamma may play an important role in the pathogenesis of NL with hemophagocytic syndrome.