In-111 octreotide scan in a case of a neuroendocrine tumor of unknown origin

Major neuroendocrine tumors contain many somatostatin receptors. This featu re allows for the localization of primary tumors and tumor metastases by sc intigraphy with the radiolabeled somatostatin analog octreotide. We describ e a patient with nonspecific clinical data and ultrasonography and CT that showed an isolated focal lesion in the liver. In-111 octreotide scintigraph y was essential in establishing the diagnosis of liver metastasis from a ne uroendocrine tumor confirmed by pathologic findings. Because clinical sympt oms recurred, ultrasonography and CT were performed a few months after surg ery. Both were negative. However, In-111 octreotide scintigraphy suggested multiple bone metastases and established the diagnosis of bone metastases f rom a neuroendocrine tumor, which was confirmed by Tc-99m MDP bone scans an d MRI.