caa a22 4500 605493537 CHVBK 20210128100521.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s00261-015-0458-0 doi (NATIONALLICENCE)springer-10.1007/s00261-015-0458-0 Non-hyperfunctioning pancreatic endocrine tumors: multimodality imaging features with histopathological correlation [Elektronische Daten] [Peter Humphrey, Francesco Alessandrino, Andrew Bellizzi, Koenraad Mortele] Purpose: To evaluate the multimodality imaging features of non-hyperfunctioning pancreatic endocrine tumors (NF-PNET) with histopathological correlation. Methods: Preoperative imaging (CT: n=23; MRI: n=14; 111In-octreotide: n=8) of 28 patients (17 female; mean age 55years) with resected NF-PNET were evaluated for tumor location, size, morphology, attenuation/signal intensity, 111In-octreotide uptake, cystic degeneration, and enhancement. Tissue specimens were assessed for the extent of stromal fibrosis, vascular density, presence of a fibrous pseudocapsule, and tumor grading. Correlation between imaging and histopathology was made using the Fisher-Freeman-Halton exact test. Results: NF-PNET arose from the pancreatic head/neck (n=10), body (n=7), and tail (n=11). On CT, NF-PNET (mean largest diameter: 4.4cm) appeared predominantly solid (69.6%), well defined (91.3%), and oval (47.8%) in shape. In the late arterial phase, NF-PNET appeared mainly hypovascular (55.5%). Septations (30.4%) and calcifications (21.7%) were relatively uncommon. On MRI, NF-PNET (mean size: 2.6cm) appeared most commonly as solid (57.1%), encapsulated (71.4%), oval (64.2%) lesions that were hyperintense on T2-WI (64.3%), and hypo- or isovascular to pancreas (66.7%) during the late arterial phase. Cystic NF-PNET (3.8cm) were not significantly larger than solid (3.5cm) NF-PNET (CT, p=0.758; MRI, p=0.451). 111In-octreotide uptake was demonstrated in 5/8 (62.5%) patients. At histopathology, NF-PNET were predominantly encapsulated (69.2%); stromal fibrosis comprised <33% of the tumor (69.2%), and vascular density was average (46.1%). A significant association was demonstrated between the degree of fibrosis and hypointensity on T2-WI (p=0.003). Vascular density, tumor grade, and degree of fibrosis did not significantly relate to the pattern of enhancement. Conclusions: NF-PNETs have variable imaging appearances but are most commonly oval shaped, solid, and well-defined/encapsulated masses, and hypovascular on late arterial and portal venous phase. Cystic degeneration in NF-PNET appears independent of tumor size. Low signal intensity on T2-WI correlates with extensive intratumoral fibrosis. Springer Science+Business Media New York, 2015 Pancreas nationallicence Neuroendocrine tumors nationallicence Non-hyperfunctioning neuroendocrine tumors nationallicence Magnetic resonance imaging nationallicence Multidetector computed tomography nationallicence Somatostatin receptor scintigraphy nationallicence Humphrey Peter Northwest Imaging, Kalispell Regional Medical Center, 59901, Kalispell, MT, USA aut Alessandrino Francesco Division of Body MRI, Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Ansin 224, 02215, Boston, MA, USA aut Bellizzi Andrew Department of Pathology, University of Iowa Carver College of Medicine, 52242, Iowa City, IA, USA aut Mortele Koenraad Division of Abdominal Imaging and Intervention, Department of Radiology, Brigham & Women's Hospital, Harvard Medical School, 02115, Boston, MA, USA aut Abdominal Imaging Springer US; http://www.springer-ny.com 40/7(2015-10-01), 2398-2410 0942-8925 40:7<2398 2015 40 261 https://doi.org/10.1007/s00261-015-0458-0 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00261-015-0458-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Humphrey Peter Northwest Imaging, Kalispell Regional Medical Center, 59901, Kalispell, MT, USA aut NATIONALLICENCE 700 1- Alessandrino Francesco Division of Body MRI, Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Ansin 224, 02215, Boston, MA, USA aut NATIONALLICENCE 700 1- Bellizzi Andrew Department of Pathology, University of Iowa Carver College of Medicine, 52242, Iowa City, IA, USA aut NATIONALLICENCE 700 1- Mortele Koenraad Division of Abdominal Imaging and Intervention, Department of Radiology, Brigham & Women's Hospital, Harvard Medical School, 02115, Boston, MA, USA aut NATIONALLICENCE 773 0- Abdominal Imaging Springer US; http://www.springer-ny.com 40/7(2015-10-01), 2398-2410 0942-8925 40:7<2398 2015 40 261