MR imaging findings of cervical lymphadenopathy in patients with Kikuchi disease

Abstract Purpose The purpose of this study was to describe the MR imaging findings of cervical lymphadenopathy in patients with Kikuchi disease (histiocytic necrotizing lymphadenitis). Materials and methods Nine patients with Kikuchi disease underwent MR imaging with a 1.5 T unit including diffusion-weighted (DW) imaging and five of nine underwent gadolinium-enhanced MR imaging. MR images were reviewed for numbers, sizes, locations, focal hypointense areas on T2-weighted images, focal non-enhancing areas on gadolinium-enhanced MR images, and apparent diffusion coefficients (ADCs) of enlarged lymph nodes. Results 52 enlarged nodes (range, 2–11 nodes; mean, 5.8 nodes per patients) were identified. Lymphadenopathy was unilateral in 7 patients (78%) and bilateral in 2 (22%). Enlarged nodes were located at level IIA in 7 nodes, IIB in 23, III in 8, IV in 4, VA in 2, and VB in 8. Focal hypointense areas on T2-weighted images were found in 7 patients (78%) and 21 nodes (40%), and had a peripheral distribution in 19 nodes (90%) and had clear margins in 16 nodes (76%). Focal non-enhancing areas were seen in 3 patients (60%) and 6 nodes (23%). ADCs were variable (range, 0.69–1.78 [×10−3 mm2 /s]; mean, 1.01 ± 0.28). Conclusion Cervical lymphadenopathy in Kikuchi disease showed predominantly a unilateral distribution at levels II–V. Furthermore, Kikuchi disease should be considered when T2-weighted images demonstrate hypointensity areas at the peripheries of enlarged cervical nodes, which corresponded to histopathological findings of coagulative necrosis in paracortical areas.