ULTRASOUND DIAGNOSIS OF METASTATIC MELANOMA OF THE GALLBLADDER

The abdominal ultrasound examinations of 464 patients with malignant m elanoma performed over a 3 year period were reviewed. 23 (5.2%) had so ft tissue material attached to the gallbladder wall and projecting int o the lumen. Four of these were polyps of less than 1 cm which were th ought to be benign, while the remaining 19 had abnormalities likely to be metastatic melanoma. Upper abdominal ultrasound examinations are f requently requested for staging purposes in patients with thick high g rade malignant melanoma or clinical suspicion of metastases. Ultrasoun d clearly identifies the gallbladder and biliary tree in the vast majo rity of patients and is generally regarded as the imaging modality of choice for suspected gallbladder pathology. As autopsy studies have co nfirmed the incidence of gallbladder metastases from malignant melanom a to be 15-20%, a careful review of the gallbladder is advocated when abdominal ultrasound examinations are performed on patients with malig nant melanoma.