A 47 yo woman presented to our clinic with a diagnosis of resected left thigh low grade leiomyosarcoma and “metastatic pancreatic neuroendocrine tumor to the lungs” . She had noticed slowly increasing size of the anterior region of her left thigh for several years; however, secondary to insurance issues had not sought medical care nor had undergone a biopsy of the mass. Two years prior to her visit to our clinic she underwent a biopsy of the thigh mass, which revealed smooth muscle neoplasm consistent with low grade leiomyosarcoma. The immunostains for smooth muscle actin, desmin, calponin were positive; immunostains for S100, CD34, CD117 were negative. The MID-I revealed 5% of the cells were proliferating. There were 2 mitotic figures per 50 high power fields. The tumor was 4.5 cm in dimention and the margins were positive. The patient subsequently underwent a PET scan for staging and was discovered to have numerous lung lesions which were not FDG avid, the largest being 2.1 cm, as well as a 4.8 x 3.3cm mass in the tail of the pancreas which was PET avid. Next, the patient underwent CT guided fine needle aspiration of the FDG avid pancreatic lesions. The biopsy was consistent with neuroendocrine carcinoma of the pancreas. An assumption was made by the previous oncology team that the numerous lung lesions were metastatic neuroendocrine tumors of the pancreas. She was then initiated on long acting octreotide injections for symptomatic relief of ongoing diarrhea and facial f lushing, and did not receive any local therapy to the pancreatic tumor. Following the octreotide injections, her symptoms of facial f lushing and diarrhea improved. At this point, approximately 24 months after initial diagnosis of pancreatic neuroendocine adenocarcinoma, she presented to the University of Miami Sylvester Comprehensive Cancer Center GI oncology clinic with symptoms of facial flushing and diarrhea, as she had not received any octreotide injections due to a lapse of insurance. Imaging done at our institution revealed a 4.8 x 3.3cm mass in the tail of the pancreas. CT of the chest revealed multiple bilateral noncalcified pulmonary nodules greater than 20 in left lung, largest measuring 1.3cm, and greater than 30 pulmonary nodules throughout the right lung, largest measuring 2.5cm. Based on outside reports the size of lung lesions had been stable over the preceeding 24 months. Subsequently, an Indium-111 Pentetreotide scintigraphy scan with SPECT imaging revealed an abnormal radiotracer accumulation in the region just antero-medially to the spleen at the level of the pancreatic tail but no abnormal activity noted in the lung lesions.

Pancreatic and peripancreatic neuroendocrine tumors are uncommon neoplasms with an annual incidence of five cases per million persons. The first account of an islet cell tumor of the pancreas was published in 1902 by Nicholls. In 1927 Wilder at El reported the first malignant pancreatic endocrine tumor, an insulinoma that had infiltrated most of the pancreas and metastasized to the liver in 1929. Several other clinical syndromes have been described for tumors producing gastrin, glucagon, vasoactive intestinal polypeptide (VIP), and somatostatin. Although Priest and Alexander (11) first described the association of an islet cell tumor with severe watery diarrhea, Vernon et al (12) further defined the syndrome now known to be related to excess circulation in VIP. The somatostatinoma syndrome was first reported in 1977 by Ganda et al who described a woman with diabetes, cholelithiasis, and a pancreatic tumor demonstrating high levels of somatostatin. For neuroendocrine tumors of the pancreas and periampullary region, the main role for surgery in non metastatic disease and selected cases of metastatic disease is for an intent to cure. Since functional tumors are diagnosed earlier than nonfunctional tumors, they have less of a chance of hav ing metastasized, and therefore, have a more favorable prognosis. Patients with functional tumors have a significantly better 5-year survival (77%) as compared to those with nonfunctional tumors (52%, P=0.025) (13,14). Somatostatin receptor scintigraphy (SRS) is a useful imaging modality for the detection of neuroendocrine tumors (15-17). Over 90 percent of gastroenteropancreatic NETs, including non-functioning pancreatic islet cell tumors and carcinoids, contain high concentrations of somatostatin receptors and can be imaged using a radiolabeled form of the somatostatin analog octreotide (indium-111 [111-In] pentetreotide, OctreoScan) (15,16,17). Although not yet clinically available, two positron emission tomography (PET) tracers for functional imaging have emerged (18-F-dihydroxy-phenyl-alanine [18F-DOPA] and 11-C-5-hydroxytryptophan [11-C-5-HTP]), which, in combination with high resolution PET, holds promise for improved detection and staging of NETs in the future. In a study of patients with carcinoid (n=24) or pancreatic islet cell tumor (n=23) who had at least one lesion on conventional imaging, integrated PET/CT imaging with 18F-DOPA had a diagnostic sensitivity of 98 percent for carcinoid tumors, compared to 49, 73, and 63 percent for SRS, SRS/CT and CT alone, respectively (18). In our case, SRS was accurate in predicting that lung metastases were not of neuroendocrine origin. The most common site of metastases for pancreatic neuroendocrine tumors is the liver. Pulmonary metastases are rare.