Canine neuroendocrine tumors of the pancreas: a study using image analysis techniques for the discrimination of metastatic versus nonmetastatic tumors.
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Canine pancreatic neuroendocrine tumors were studied using different image analysis techniques (nuclear image histometry, analysis of argyrophilic proteins of nucleolar organizer regions, determination of the mouse anti-Ki 67 antigen proliferation index, and DNA densitometry) to correlate their biological behavior with objective phenotypic markers. The methods were compared to determine the best method for distinguishing between metastatic and nonmetastatic tumors. Discrimination between the two types of tumor was possible using nuclear image histometry in combination with morphometric analysis of argyrophilic proteins of nucleolar organizer regions. In contrast, the mouse anti-Ki 67 antigen proliferation index, DNA measurement, and immunohistochemical parameters revealed no significant difference between the two types of tumors. (+info)
Expression of peptide receptors in human endocrine tumours of the pancreas.
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BACKGROUND: Gut peptides are known to influence hormone release and growth of endocrine tumours of the pancreas. Although information on somatostatin receptors has been provided recently, little is known on the receptor status of other gastrointestinal hormones in such tumours. AIMS: To analyse the spectrum of gut hormone receptors on endocrine tumours of pancreas. SUBJECTS: Four types of endocrine tumours from eight patientS. METHODS: The receptors for bombesin, secretin, vasoactive intestinal peptide, cholecystokinin, and somatostatin have been visualised and quantified with storage phosphor autoradiography. RESULTS: Bombesin receptors were present in all five gastrinomas and two primary VIPomas. Secretin receptors were expressed in four primary gastrinomas and one primary VIPoma from pancreas. Vasoactive intestinal peptide receptors were identified in four primary gastrinomas and all VIPomas. Furthermore, all VIPomas expressed cholecystokinin-B (gastrin) receptors, whereas, gastrinomas did not contain cholecystokinin-B receptors. The receptors for somatostatin were detected in all gastrinomas and VIPomas. Both somatostatinoma and glucagonoma were negative for all five types of peptide receptors studied. CONCLUSIONS: Besides somatostatin receptors, most of gastrinomas and VIPomas also express receptors for bombesin, secretin, and vasoactive intestinal peptide. (+info)
Usefulness of magnetic resonance imaging with dynamic contrast enhancement and fat suppression in detecting a pancreatic tumor.
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The purpose of this study was to compare the value of dynamic magnetic resonance imaging (MRI) and fat suppression in detecting a pancreatic tumor. The subjects were 19 patients with invasive ductal adenocarcinoma and six patients with islet cell tumor where diagnosis was established pathologically. Breath-hold gradient echo images, breath-hold gradient echo images with fat suppression and breath-hold gradient echo images with dynamic enhancement at 1.5 T were obtained for all patients. The efficacies of these three imaging techniques were compared by calculating the contrast-to-noise ratio, as indicative of conspicuousness between a tumor-affected and a normal pancreas. As for adenocarcinoma, our results indicated that the usefulness in detecting the tumor was high, decreasing in the order dynamic contrast images > fat suppression images > plain images, and that the difference between any two of these three types of image was statistically significant. On the other hand, these imaging techniques showed no statistically significant difference in detecting islet cell tumors. In conclusion, dynamic MRI is the best method for detecting pancreatic adenocarcinoma. As the fat suppression technique has the advantage of being non-invasive, this method is suitable for screening studies of pancreatic adenocarcinoma. However, no advantage was recognized in using the fat suppression technique for detecting an islet cell tumor in comparison with plain MRI. (+info)