Kikuchi-Fujimoto Disease in a 15-Year-Old Girl: Presenting With Fever and Cervical Lymphadenopathy

Background: Kikuchi-Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a rare, benign, self-limiting disorder that commonly affects adolescents and young women. Its clinical presentation frequently resembles tuberculous lymphadenitis or lymphoma, making diagnosis challenging, particularly in tuberculosis-endemic countries. Case Presentation: A 15-year-old girl presented with fever and left-sided cervical lymphadenopathy. Laboratory investigations showed mild anemia, leukopenia, elevated ESR, normal CRP, and negative infectious work-up for dengue, malaria, typhoid, and chest radiography. Fine needle aspiration cytology suggested granulomatous lymphadenitis with no acid-fast bacilli identified. Because of persistent lymphadenopathy, an excision biopsy was performed. Histopathology demonstrated necrotizing lymphadenitis with abundant karyorrhectic debris, absence of well-formed granulomas, giant cells, Reed-Sternberg cells, and cellular atypia. We considered Kikuchi-Fujimoto disease as an important differential diagnosis and advised immunohistochemistry (IHC). The IHC profile confirmed the diagnosis of KFD. Conclusion: This case highlights the importance of meticulous histopathological examination followed by targeted immunohistochemistry in establishing the diagnosis of KFD and avoiding unnecessary treatment for tuberculosis or lymphoma.