Usefulness of contrast enhanced ultrasonography in imaging of melanoma's gallbladder metastastasis: three cases report

Ultrasound is regarded as the imaging modality of choice for suspected gallbladder pathology. However the specificity of plain ultrsonography (US) is certainly decreased when imaging malignant affections of gallbladder. Contrast enhanced ultrasonography (CEUS) could become an interesting complementary diagnostic tool for differentiating malignant from benign disease.

Our purpose is to illustrate the role of CEUS in assessing the diagnosis of gallbladder metastasis from melanoma throughout three cases of patients.

Three patients were addressed for US examination because of indeterminate gallbladder hypo densities detected on CT. B mode US revealed polypoïd lesions in two patients and a heterogeneous content in the other one. After injection of contrast medium they presented an early arterial intense enhancement followed by a wash out. Then we concluded to the malignant nature of lesions. These findings were confirmed as melanoma metastasis by histological specimen in one patient and by TEP or MR imaging in the two other patients.

CEUS is a new functional imaging tool which is actually reported to improve sensitivity and specificity of plain US especially in liver tumoral disease. This technique seems to be a powerful imaging tool even in other abdominal areas such as gallbladder for characterizing as malignant some undetermined lesions.