Comparison of Ultrasound Features of Major Salivary Glands in Sarcoidosis, Amyloidosis, and Sjogren's Syndrome

Objective While salivary gland ultrasound (SGU) has gained prominence for evaluating Sjogren's syndrome, little information exists onSGUappearance of sarcoidosis and amyloidosis, potential mimics of Sjogren's syndrome. Our goal in this study was to estimate the diagnostic accuracy of majorSGUfeatures in differentiating Sjogren's syndrome from sarcoidosis, amyloidosis, and controls. Methods We enrolled consecutive adult ambulatory patients with a clinical diagnosis of Sjogren's syndrome fulfilling the 2016 American College of Rheumatology (ACR) classification criteria; we also enrolled patients with a clinical diagnosis of sarcoidosis or systemic immunoglobulin light chain (AL) amyloidosis, with histologic confirmation from any tissue, and rheumatology outpatients without diagnoses affecting salivary glands. Subjects underwent majorSGUusing the Hocevar protocol, with resulting video clips reviewed blind to clinical diagnosis. Results Sjogren's syndromeSGUscores were greater than in patients from the other groups, but there were no distinguishing salivary gland features fromALamyloidosis or sarcoidosis. None of the patients in the control group scored higher than 17, a cutoff previously suggested for Sjogren's syndrome, but 27% of patients withALamyloidosis and 19% with sarcoidosis scored higher than 17. Adding HocevarSGUscores of >= 17 to the 2016ACR/European League Against Rheumatism criteria in a parallel scheme increased the sensitivity for Sjogren's syndrome from 87% to 98%, while combining the 2 criteria in series increased specificity from 81% to 98%. Conclusion Sjogren's syndrome, sarcoidosis, andALamyloidosis share commonSGUfeatures that can help distinguish these conditions from patients without systemic rheumatologic disease. Clinicians should carefully consider these potential mimics when interpreting salivary glandUSresults.