Purpose. The aim of this study was to characterize the gray-scale sonographic findings in the lymph nodes of patients with cat-scratch disease (CSD). Methods. We analyzed the sonograms of cervical lymph nodes in 41 patients with proven CSD between January 1997 and October 1999. Results. A total of 222 involved lymph nodes were detected. Involved nodes were most commonly found in the middle cervical (58%), parotid (37%), upper cervical (37%), and submandibular (17%) regions. We found acute, chronic, or abscessed lymphadenopathy in 63%, 12%, and 24% of patients, respectively. The size of involved lymph nodes ranged from 12 x 4 mm to 35 x 26 mm. The largest involved node had a short axis/long axis ratio of 0.5 or more in 61% of patients. Useful features for the differential diagnosis included markedly decreased echogenicity (100%), normal surrounding tissues(100%), and the presence of an echogenic hilum (76%). Posterior sound enhancement was significantly associated with larger and abscessed lymph nodes. Conclusions. Despite the absence of a specific sonographic finding for CSD, gray-scale sonography can provide clues to the diagnosis of CSD in the proper clinical setting. (C) 2001 John Wiley & Sons, Inc.
