Comparison of Ultrasonographic Findings of Biopsy-Proven Tuberculous Lymphadenitis and Kikuchi Disease

Abstract

Objective: Although tuberculous lymphadenitis and Kikuchi disease are common causes of cervical lymphadenopathy in Asians and exhibit similar clinical manifestations, their treatment strategies are totally different. The purpose of this study was to identify ultrasonographic features that distinguish these two diseases.

Materials and methods: This study was approved by the Institutional Review Board. The study included 77 patients with tuberculous lymphadenitis and 135 patients with Kikuchi disease. The sex and age distributions of the patients were analyzed. The size and shape of lymph nodes (LNs), presence of conglomeration, increased perinodal echogenicity, echogenic hilum, posterior neck involvement, internal calcification, patterns of internal necrosis, laterality of involved LNs, and hilar vascular patterns on ultrasonography were compared between the two groups. Multiple logistic regression analysis was conducted to identify independent findings to discriminate tuberculous lymphadenitis from Kikuchi disease. Finally, diagnostic accuracies were calculated using the independent findings.

Results: The presence of an echogenic hilum, internal calcification, patterns of internal necrosis, and LN hilar vascular structures on power Doppler ultrasonography were independent findings that discriminated tuberculous lymphadenitis from Kikuchi disease. The diagnostic accuracy of each of these four factors was 84.9% (181/212), 76.9% (163/212), 84% (178/212), and 89.2% (189/212), respectively. A combination of internal calcification and hilar vascular structures showed the best accuracy of 89.6% (190/212) (sensitivity, 86.7% [117/135]; specificity, 94.8% [73/77]) for diagnosing Kikuchi disease.

Conclusion: The presence of an echogenic hilum, internal calcification, pattern of internal necrosis, and LN hilar vascular structures are useful ultrasonographic findings to differentiate tuberculous lymphadenitis from Kikuchi disease.

Keywords: Kikuchi disease; Tuberculosis; Tuberculous lymphadenitis; Ultrasonography.

Fig. 1. 54-year-old woman with tuberculous lymphadenitis.

A, B. Conglomerated cervical lymphadenopathies show increased perinodal echogenicity (arrows) on ultrasonography (A) and increased perinodal attenuation (white circle) on computed tomography scan (B).

Fig. 2. 26-year-old woman with Kikuchi disease

Cervical lymph node shows increased perinodal echogenicity (arrows).

Fig. 3. 40-year-old woman diagnosed with tuberculous lymphadenitis.

A, B. Enlarged cervical lymph node shows gross internal necrosis and no definite echogenic hilum on gray-scale ultrasonography (A) and avascular pattern on power Doppler ultrasonography (B).

Fig. 4. 37-year-old man diagnosed with Kikuchi disease.

A, B. Elongated cervical lymph node shows internal echogenic hilum (asterisk) and no definite necrotic component on gray-scale ultrasonography (A) and normal hilar vascular pattern on power Doppler ultrasonography (B). C. Axial computed tomography scan shows definite necrosis at same lymph node (arrow).

Fig. 5. 59-year-old man with tuberculous lymphadenitis.

A. Small cervical lymph node shows internal hyperechoic lesions (arrows) with some posterior acoustic shadowing (asterisk) interpreted as calcification. B. No calcification was detected on computed tomography scan of same lymph nodes (arrow).