Purpose or Case Report: Histiocytic necrotizing lymphadenitis, also known as Kikuchi-Fujimoto disease, is a benign, self-limited disorder, associated with B symptoms (fever, weight loss) and painful lymphadenopathy. The combination of lymphadenopathy with B symptoms in the pediatric population raises suspicion for malignant diseases such as lymphoma, neuroblastoma, and rhabdomyosarcoma. We evaluated a series of children with biopsy-proven histiocytic necrotizing lymphadenitis to assess for unique imaging characteristics.
Methods & Materials:
Results: We performed a retrospective review from 2013 to 2023 at a single tertiary care children’s hospital for biopsy-proven histiocytic necrotizing lymphadenitis. We report five pediatric patients presenting with fever, weight loss, and painful lymphadenopathy. Three were female and median age was 17 years. All underwent excisional biopsy. The sites of lymphadenopathy were as follows: 2/5 (40%) unilateral cervical, 1/5 (20%) bilateral cervical, 1/5 (20%) bilateral supraclavicular and axillary, and 1/5 (20%) mesenteric.

All patients underwent contrast-enhanced CT showing homogenous enlargement of lymph nodes with concern for malignancy. Interestingly, all showed an apparent positive relationship between the size and extent of necrotic changes with smaller-sized nodes having punctate multifocal necrosis and the larger nodes having more confluent necrosis. All showed perinodal infiltration with the degree of infiltration proportional to nodal size. There was no encasement of the adjacent abdominal vessels in the child with mesenteric adenopathy, which often occurs with lymphoma and neuroblastoma. 2/5 underwent PET/CT with FDG avidity ranging between maximum SUVs of 7 and 13.
Conclusions: In the setting of worrisome lymphadenopathy in children, it is important to consider benign entities such as the indolent histiocytic necrotizing lymphadenitis, especially if there is perinodal infiltration and nodal necrosis. As clinical symptoms overlap, other benign entities such as granulomatous disorders would also be included in the differential diagnosis.