Internal medicine

Radiology

Pathology

Neuroendocrine tumors

Octreotide

Lesion

Cancer

Somatostatin

Malignancy

Adenocarcinoma

Medicine

The American Journal of Gastroenterology

INTRODUCTION: Neuroendocrine tumors (NETs) are rare malignancies, defined at a cellular level by the presence of somatostatin receptors, which has recently been exploited in the development of positron-emitting somatostatin analogs for use in the 68-Gallium DOTATATE PET scan (hereafter “Dotatate scan”). Compared to previously-used technology, the Dotatate scan has shown dramatic improvements in sensitivity for lesion detection. The Dotatate scan exposes patients to lower doses of radiation, and is completed much more quickly. We present a case of a new diagnosis of a neuroendocrine tumor that illustrates multiple benefits of Dotatate scan including improved lesion detection and characterization which quickly led to changes in the treatment plan for a patient who previously was given a presumptive diagnosis of advanced pancreatic adenocarcinoma. CASE DESCRIPTION/METHODS: A 52-year-old man with history of two episodes of pancreatitis presented with one day of acute-onset epigastric pain, diarrhea, and nausea. Initial ultrasound and computed tomography (CT) scan demonstrated numerous hypervascular lesions in the liver, a mesenteric mass with associated lymphadenopathy, and a possible pancreatic tail lesion, leading to clinical concern for pancreatic adenocarcinoma. Upon further questioning, the patient reported 12–18 months of intermittent flushing and rash. A Dotatate scan revealed increased avidity in the hepatic and mesenteric lesions suggestive of carcinoid malignancy. The improved lesion characterizations provided by the Dotatate scan were useful for identifying the larger small bowel lesion as the likely primary tumor, as well as for surgical planning for debulking. Subsequent serum and urine tests were consistent with carcinoid malignancy, and a biopsy of a liver lesion confirmed the diagnosis of metastatic carcinoid tumor. The pancreatic lesion also demonstrated uptake on the scan, most consistent with a metastasis to the pancreas, with a confirmatory biopsy via endoscopic ultrasound pending. DISCUSSION: We demonstrate the utility of the Dotatate scan to support the rapid diagnosis of a neuroendocrine tumor, to assist in identification of the likely primary lesion, and to better characterize the extent of disease. Dotatate scans have been infrequently used due to novelty and cost, but cases such as this demonstrate that the cost can be well-justified in the right clinical setting.

2609 Use of Dotatate Scan to Establish Diagnosis of a Neuroendocrine Tumor