Sonographic features of axillary lymphadenopathy caused by Kikuchi disease

The purpose of this study was to document the sonographic findings of axillary lymphadenopathy in Kikuchi disease.

The medical records and sonographic findings of 7 patients with a pathologic diagnosis of Kikuchi disease in the axillary lymph node by sonographically guided core needle biopsy (n=6) or excisional biopsy (n=1) were reviewed. On sonograms, lymph nodes were assessed for their distribution, size, shape, border, echogenicity, and internal architecture, and those sonographic features of each node were evaluated to determine whether the findings favored malignant or benign lymphadenopathy.

Of the 7 patients (1 man and 6 women; mean age +/- SD, 34.3+/-7.7 years), 29 affected lymph nodes (5-38 mm; mean, 14.8+/-7.2 mm) were identified on sonograms. The sonographic characteristics were as follows: the shortest axis/longest axis ratio of the node (mean, 0.595) was 0.5 or greater in 22 nodes (76%); the border was sharp in 16 (55%); the cortex was hypoechoic in 20 (69%) and isoechoic in 9 (31%); the hilum was narrow in 1 (4%) and absent in 16 (55%); and cortical thickening was found in 13 (45%, concentric in 6 and eccentric in 7). Nineteen lymph nodes (66%) were classified as having malignant-favoring features, and 10 (34%) were classified as having benign-favoring features.

Many axillary lymph nodes in Kikuchi disease look suspicious sonographically. When lymph nodes in the axilla show suspicious findings on sonograms of relatively young patients, Kikuchi disease can be considered a possible differential diagnosis, and image-guided percutaneous biopsy should be done.