MR imaging findings of cervical lymphadenopathy in patients with Kikuchi disease.

Objective: The purpose of this study was to describe the MR imaging findings of cervical lymphadenopathy in patients with Kikuchi disease (histiocytic necrotizing lymphadenitis).

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).

Conclusions: 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.