Somatostatin receptor scintigraphy of malignant somatostatinoma with indium-111-pentetreotide.

This article describes the visualization of a pancreatic somatostatinoma and liver metastases using 111In-pentetreotide imaging in a patient with somatostatinoma syndrome. A 61-yr-old woman with gallbladder stones, diabetes, weight loss, diarrhea and steatorrhea, immunohistochemical diagnosis of somatostatinoma (liver biopsy) and high plasma values of somatostatin was studied by somatostatin receptor scintigraphy. Six sites of focal abnormal 111In-pentetreotide hyperfixation were found: three in the liver and three in the pancreatic area. This case report demonstrates that in vivo detection of somatostatinoma with somatostatin receptor imaging is possible in the presence of high levels of circulating somatostatin, suggesting that receptor downregulation has not occurred.