Imaging presentation of pancreatic neuroendocrine neoplasms

Abstract

Pancreatic neuroendocrine neoplasms (P-NENs) are the second most common solid pancreatic neoplasms. P-NENs have a wide range of imaging features presentations and they can be detected with typical and atypical imaging presentations. Typical and atypical appearances can be explained by pathologic correlations. P-NENs are generally hypervascular lesions, showing a typical enhancement behavior after contrast media injection during imaging methods, but they could also have different imaging features, creating some difficulty in differential diagnosis. For this reason, radiologists should be aware of different imaging presentations of these neoplasms. Radiological evaluation has a critical role in P-NENs identification, characterization, and staging of these neoplasms, especially in those cases in which surgery is the treatment of choice. The present paper shows, indicating the underlying pathologic correlations, typical and atypical presentations of NENs.Key Points• P-NENs have a wide range of imaging features presentations, typical and atypical.• Pathology could help in better understanding the typical P-NENs appearance at imaging.• P-NENs are generally hypervascular lesions.• Radiological evaluation has a critical role in P-NENs identification and management.• Radiologists should know every type of different imaging presentation of P-NENs to better diagnose these kinds of lesions.

Imaging of Pancreatic Neuroendocrine Neoplasms

“…At pre-contrast CT examination, panNENs typically appear as well-rounded, isodense or slightly hypo-dense lesions, with a homogeneous pattern and regular margins [28]. Following the administration of intravenous contrast material, panNENs typically tend to hyper-enhance during arterial phase and demonstrate a slow washout, appearing hyper-dense or isodense among the surrounding parenchyma during portal phase (Figure 1) [29,30]. This typical presentation is more frequently seen in functioning tumors; non-functioning panNENs, especially large ones, more often tend to have an atypical appearance.…”

Current update on imaging for pancreatic neuroendocrine neoplasms

“…Common manifestations include necrolytic migratory erythema, diabetes mellitus, deep vein thrombosis, and depression[ 3 , 6 , 7 ]. Other functioning panNET are somatostatinomas, vasoactive intestinal peptide-secreting tumors, and adrenocorticotropic hormone-secreting tumors, which comprise less than 20% of cases[ 8 ].…”

“…On sonography, panNEN usually appear as a well-defined, solid, heterogeneous hypoechoic mass (Figure 1 ). Some lesions may present with cystic regions[ 8 , 10 ]. Hepatic metastases from panNEN are often hyperechoic in comparison to surrounding liver parenchyma, however they can also manifest as hypoechoic and targetoid lesions.…”

“…Nonfunctioning panNET are usually larger, heterogeneously enhancing masses, and are more likely to exhibit local or vascular spread. Necrosis, cystic changes, and calcifications may be observed[ 1 , 8 ]. Larger nonfunctioning panNET are more likely to exhibit aggressive behavior and often present with metastatic disease.…”

Update on current pancreatic treatments: from molecular pathways to treatment

“…There are underlying pathologic correlations with typical and atypical presentations of pancreatic neuroendocrine neoplasms 74. Liquid biopsy could be a tool to assess potential biomarkers.…”