Contrast-enhanced ultrasonography in differential diagnosis of focal gallbladder adenomyomatosis and gallbladder cancer

BACKGROUND: Focal gallbladder adenomyomatosis (ADM) is a common disease that mimics gallbladder cancer (GBC) on ultrasonography. OBJECTIVE: Here we aim to assess the value of contrast-enhanced ultrasound (CEUS) in differentiating ADM from GBC. METHODS: Forty-one histopathologically proven focal ADMs and 34 GBCs (≤T2 stage) were enrolled in the study. Lesion location, blood flow signals, contrast pattern and appearance on contrast-enhanced ultrasound (CEUS) were compared respectively. RESULTS: Lesions were detected in fundus, body, neck at the rates of 61.0% (25/41), 26.8% (11/41) and 12.2% (5/41), respectively, in ADM patients, in comparison to 29.4% (10/34), 32.4% (11/34) and 38.2% (13/34), respectively, in GBC patients (p = 0.009). Blood flow signals were detected in 19.5% (8/41) of cases in ADMs, compared to 58.8% (20/34) in GBCs (p = 0.001). On CEUS, iso-enhancement, hypo-enhancement, intramural anechoic space and intactness of GB wall were detected in 41.5% (17/41), 39.0% (16/41), 56.1% (23/41) and 80.5% (33/41) cases of ADMs, in contrast to 17.6% (6/34), 20.6% (7/34), 20.6% (7/34) and 17.6% (6/34) of GBCs (p = 0.001, p = 0.001, p = 0.002, p < 0.001, respectively). The prior Youden's index were 0.81 based on intactness of GB wall on CEUS. CONCLUSION: Combined with CEUS helps improve the differential diagnosis accuracy of focal gallbladder ADMs.