1. The study included 15 patients with fever of unknown origin who were diagnosed with histiocytic necrotizing lymphadenitis.
2. All patients presented with fever and cervical lymphadenopathy, with an average fever duration of 36 days.
3. Laboratory findings showed leukopenia in 60% of patients, anemia in 47%, and frequently elevated inflammatory markers.
4. PET/CT demonstrated hypermetabolic lymph nodes in 13 of 15 patients, but 73% were misclassified as having other diseases.
5. Biopsies revealed disrupted nodal architecture, coagulative necrosis, karyorrhectic debris, and absence of neutrophils.
6. All patients were treated with corticosteroids, 3 also received intravenous immunoglobulin, and all improved.
7. During more than 3 years of follow-up, 1 patient experienced recurrence and 1 developed systemic lupus erythematosus.
8. The researchers emphasized that biopsy is essential to distinguish histiocytic necrotizing lymphadenitis from lymphoma.

Source: Diagnostic Pathology