Hye Jin Baek, Presenter: Nothing to Disclose

Jeong Hyun Lee MD, PhD, Abstract Co-Author: Nothing to Disclose

Jung Hwan Baek, Abstract Co-Author: Nothing to Disclose

Hyun Kyung Lim MD, Abstract Co-Author: Nothing to Disclose

Ha Young Lee MD, Abstract Co-Author: Nothing to Disclose

Jee Won Park MD, Abstract Co-Author: Nothing to Disclose

Kikuchi’s disease (KD) and tuberculous lymphadenitis (TB) are common causes of necrotizing lymphadenitis in young adults and well-known to have similar imaging features on neck CT. The purpose of this study was to define the role of CT for differentiation of KD and TB.

From 2006 to 2010, 87 consecutive patients who underwent an excisional (n=8), US-guided fine needle aspiration (n=69) or core needle (n=10) biopsy of a cervical lymph node and finally diagnosed with KD or TB were enrolled in this study. Clinical features including presenting symptoms were investigated with medical records. Two radiologists performed independent analysis of contrast-enhanced neck CT scans about the followings blinded to the final diagnosis: the number of the affected nodal levels, presence of necrosis, contrast enhancement or calcification, bilaterality of involvement, perinodal infiltration, and presence of upper lung lesion or mediastinal lymphadenopathy. A χ2 test, ROC and logistic regression analyses were performed. Sensitivity, specificity, and positive and negative predictive values were obtained.

ROC analysis revealed that > 5 nodal levels of involvement was a significant diagnostic cut-off of KD with Az value of 0.765 (95% CI, 0.690 – 0.839). Statistically significant findings of KD were the presence of fever (p<0.001), age (mean: 26.9 for KD vs 40.1 for TB, p<0.001), necrosis < 1/2 of affected lymph nodes (sensitivity, 90.7%; specificity,79.1%), bilaterality (sensitivity,60% ; specificity,71.7%) and > 5 nodal levels of involvement (sensitivity,63% ; specificity,80.8%). The CT findings of TB were mediastinal lymphadenopathy (sensitivity,35.8%; specificity,96.3%), upper lung lesion (sensitivity, 40.8%; specificity, 94.4%), calcification (sensitivity,19.2% ; specificity,100%) and complications such as abscess or adjacent soft tissue involvement (sensitivity,31.7% ; specificity,100%). The presence of one of CT findings of KD had a sensitivity of 72.2%, a specificity of 77.2% and a diagnostic accuracy of 75.7%.

Awareness of the CT findings of KD and TB could be helpful for the discrimination of the two diseases with reducing unnecessary biopsies.

The typical CT findings reported above will be helpful to avoid unneccesary biopsies to differentiate KD from TB.

Baek, H, Lee, J, Baek, J, Lim, H, Lee, H, Park, J, Role of Contrast-enhanced Neck CT for Differentiation of Kikuchi Disease and Tuberculous Lymphadenitis.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11014726.html