CT findings in Kikuchi disease: Analysis of 96 cases

BACKGROUND AND PURPOSE: Although CT findings of Kikuchi disease (KD), or histiocytic necrotizing lymphadenitis, are reported in several case reports, large-scale analysis of the disease has not been undertaken. We characterized the clinical and CT findings in a large group of patients with KD. METHODS: Between 1990 and 2002, 96 patients (68 women, 28 men; mean age, 24.4 years) underwent biopsy of the cervical lymph nodes and had histologically proved KD at our institution. We reviewed their clinical and CT findings and recorded the total number of affected nodes; location and size of the lymph nodes; and characteristic findings including necrosis, perinodal infiltration, and contrast enhancement. RESULTS: We identified 1196 affected lymph nodes (12.5 nodes per patient). The affected lymph nodes were 0.5-3.5 cm (mean, 1.62 cm). Perinodal infiltration was found in 78 patients (81.3%). Eighty (83.3%) had homogeneous nodal contrast enhancement. Nine patients (9.4%) had lymph nodes with a focal low attenuation, and seven (7.3%) had ring-shaped lymph nodes. Unilateral and bilateral cervical lymph nodes were affected in 76 and 20 patients, respectively. Lymph nodes were mainly located at levels II (IIA, 174 nodes; IIB, 254 nodes), III (222 nodes), IV (160 nodes), and V (VA 126 nodes, VB 130 nodes). Follow-up CT in 32 patients showed complete resolution in 14 and partially improved lymphadenopathy in 18. CONCLUSION: Awareness of the various CT appearances of KD and follow-up CT may be helpful for more accurate diagnosis of the disease.