Incidentally Detected Focal Fundal Gallbladder Wall Thickening at Contrast-Enhanced Computed Tomography: Prevalence and Computed Tomography Features of Malignancy

Objective The aim of this study was to determine the prevalence and computed tomography (CT) features of malignancy in incidental focal fundal gallbladder wall thickening. Methods Patients with incidental focal fundal gallbladder wall thickening on CT were included if they had an ultrasound or magnetic resonance imaging diagnostic of the etiology (n = 19), stability on CT for 1 year (n = 84), or pathological correlation (n = 13). Morphologies were classified as type 1 (nodular/pinched intramural low attenuation), type 2 (intramural low attenuation), type 3 (homogeneous enhancement), type 4 (nodular/pinched homogeneous enhancement), type 5 (intramural cystic spaces), or type 6 (hyperenhancing/heterogeneous enhancement). Results One hundred sixteen patients had the following morphologies: type 1 (n = 57), type 2 (n = 10), type 3 (n = 6), type 4 (n = 19), type 5 (n = 14), and type 6 (n = 10). Four cases (3.4%; 95% confidence interval, 0.9%-8.6%) of malignancy were identified (type 6 in 3 and type 3 in 1). Conclusions Incidental focal fundal gallbladder wall thickening is usually benign. Computed tomography features help distinguish benign from malignant etiologies.