Gallbladder metastasis: spectrum of imaging findings

The objective of this study is to report the diagnostic features of hematogenous gallbladder metastasis using various imaging modalities. We carried out a single-center retrospective analysis of 13 patients with gallbladder metastasis. The primary malignancy was cutaneous melanoma (11 cases), hepatocellular carcinoma (1 case), and non-Hodgkin lymphoma (1 case). All patients underwent sonography (US), with color-power-Doppler assessment in 11 cases. Contrast-enhanced US (CEUS) was performed in 8 patients, MDCT in 8, and MR imaging in 1. Four subjects studied by whole-body PET. The gallbladder lesions were first detected with US in 9 cases and with MDCT in 3 cases. The remaining patient was investigated because of hepatic fluorodeoxyglucose uptake at PET; CEUS failed to detect any liver metastasis in this subject but identified a gallbladder lesion. Typical findings included multiplicity of gallbladder vegetations, broad base, limited mural thickening, presence of contrast enhancement, absence of gallstones and gallbladder bed infiltration, presence of combined lesions within other organs. Only two patients presented an isolated location in the gallbladder and were successfully treated with surgery. Gallbladder metastasis is a rare but possible occurrence. Knowledge of the typical imaging features and careful evaluation of the gallbladder may avoid an incorrect or false negative diagnosis.