Endoscopic Ultrasound Assessment of Pancreatic Duct Diameter Predicts Neuroendocrine Tumors and Other Pancreas Masses.

OBJECTIVES: Distinguishing neuroendocrine tumors (NETs) and other pancreas lesions from adenocarcinomas via endoscopic ultrasound (EUS) requires additional tissue for special staining and processing. Our aim was to determine if main pancreatic duct (PD) diameter on EUS helps to differentiate NET and other unusual tumors from adenocarcinoma. METHODS: We evaluated 30 consecutive patients diagnosed with NET or other pancreas lesions by EUS with 90 matched patients who were found to have adenocarcinoma. Dilated PD was defined as greater than 3 mm. Multivariate logistic regression was used to evaluate associations between lesion type and PD diameter. RESULTS: Among the 30 patients with NET/other pancreas lesions, 21 had NETs, 7 had metastases, and 2 had lymphomas. A dilated PD was demonstrated in only 3.3% of pancreatic NET/other lesions but present in 88.9% of cases of primary adenocarcinoma (P < 0.01). In multivariate analysis, a normal PD diameter and absence of clinical symptoms strongly predicted the presence of pancreatic NET/other versus adenocarcinoma (P < 0.01). CONCLUSIONS: The absence of PD dilation upstream of the lesion suggests NET or other lesions rather than adenocarcinoma. This finding should prompt endosonographers to obtain additional tissue at the time of EUS to send for special studies.

Assessment of the main pancreatic duct using computed tomography with multiplanar reconstructions.

UNLABELLED: The aim of this study was to assess the morphology of the main pancreatic duct (MPD) using multiplanar reconstructions and to compare this with the morphology of the MPD of anatomic subjects. MATERIALS AND METHODS: The morphology of the MPD was studied by means of multiplanar reconstructions obtained on the one hand from thin tomodensitometric slices and on the other hand from the dissection of anatomic subjects. This study involved 15 subjects in each group. RESULTS: Full multiplanar reconstruction was obtained in 13 cases. In 2 cases, the isthmus did not appear in the reconstructions. The morphology of the MPD was similar in both groups. The length of the MPD was identical at the head and isthmus of the pancreas in both groups but was greater in the dissection group than in the reconstruction group in the body and tail areas of the pancreas. The diameter of the MPD was greater at the head of the pancreas in the dissection group and was identical in both groups for the other segments of the MPD. CONCLUSIONS: Multiplanar tomodensitometric reconstruction of the main pancreatic duct is feasible. This new technique, currently under evaluation, could allow the study of canalar pathologies of the pancreas through tomodensitometry.

Ligation-induced acute pancreatitis in rats and opossums: a comparative morphologic study of the early phase.

Bile and pancreatic duct ligation (BPDL) in rats does not induce severe acute pancreatitis but only mild inflammation, which is self-limiting and eventually leads to pancreatic atrophy. However, BPDL in opossums induces severe acute necrotizing pancreatitis which uniformly leads to death within 14 days. We compared pancreatic morphologic changes after 24 hr of BPDL in rats and opossums. Pancreatitis histology score and acinar cell ultrastructural changes were evaluated. In both species, BPDL was associated with significant increases in histology score compared to sham controls (5.0 +/- 0.3 vs 1.5 +/- 0.3 in rats, 5.3 +/- 0.4 vs 1.1 +/- 0.1 in opossums; mean +/- SEM, ANOVA, P < 0.05). However, there was no significant difference in histology score between rats and opossums following BPDL; histologic changes, such as white blood cell infiltration, acinar cell vacuolation, and focal acinar cell necrosis, were similar. Acinar cell ultrastructural changes after BPDL in both species included dilated endoplasmic reticulum and autophagic vacuole formation. These findings indicate that the early morphologic changes after BPDL in rats are quite similar to those seen early in the course of BPDL-induced acute necrotizing pancreatitis in opossums. As the rat is a more economical and convenient model to study than the opossum, this study supports the use of the rat model to conduct pilot studies of early events in the development of BPDL-induced acute pancreatitis. This study also suggests the potential for investigating mechanisms that may be present in the rat which protect against progressive and fatal acute necrotizing pancreatitis as observed in opossums after longer periods of BPDL.