Purpose
At the state of the art,
the role of imaging in the identification of signs of malignancy of neuroendocrine pancreatic neoplasms (PNET) is based quite only on nodular dimension (according to the WHO-World Health Organization-classification system) and on the presence of local and distant spreading [1].
The aim of our study was firstly to demonstrate that a further criterion to suspect the lesion nature may be represented by their post-contrastographic behaviour.
Considering that authors [2,3] demonstrated a significant inverse correlation between the microvascular density (MVD)...
Methods and Materials
The study included 12 cases of PNET and particularly 2 adenomas,
5 borderline tumours and 5 well differentiated carcinomas submitted to MDCT study and surgical resection.
All preoperative CT examinations were performed by a multidetector CT (Light Speed Plus,
GE Medical System,
Milwaukee USA or Light Speed VCT,
GE Medical System,
Milwaukee USA).
Studies were performed by acquiring basal as well as post-contrastographic scans,
after intravenous administration of high-concentration iodinated contrast medium(Iomeron® 400).
Post-contrastographic study included 4 phases: early arterial phase (delay 15-20”); pancreatic phase...
Results
After surgical resection,
pathological analysis demonstrated 2 adenomas,
5 borderline tumours and 5 well-differentiated carcinomas.
We demonstrated that all 2 ADN were associated with pattern A.
Three out of 4 lesions showing pattern B1 were classified as BRD at histological examination while 1 out of 4 resulted to be a WDC.
Three out of 4 lesions with pattern B2 resulted to be WDC at pathology,
while 1 out of 4 was a BRD.
The remaining nodules were 1 borderline tumour and 1 well differentiated carcinoma,...
Conclusion
At the state of the art,
the best available criteria to formulate a suspicion of benignancy/malignancy of a neuroendocrine pancreatic lesion are the presence of a clinical syndrome,
the lesion dimension (according to the WHO classification system) and the presence of signs of local or distant invasion at imaging [1].
On the basis of our experience,
the lesion post-contrastographic pattern at MDCT may represent a further criterion for suspecting lesion malignancy.
In fact,
studies[4] have demonstrated an association between MVD and degrees of tumour enhancement....
References
[1] Rha,
Jung,
Lee et al.
CT and RM imaging findings of endocrine tumor of the pancreas according to WHO classification.
Eur J Radiol 2007; 62:371-7.
[2]Couvelard A,
O’Toole D,
Turley H et al.
Microvascular density and hypoxia-induciblefactor pathway in pancreatic endocrinetumours: negative correlation of microvasculardensity and VEGF expression with tumourprogression.
Br J Cancer 2005;92:94–101.
[3]Takahashi Y,
Akishima-Fukasawa Y,
Kobayashi N,
et al.
Prognostic value of tumor architecture,
tumor-associated vascular characteristics,
and expression of angiogenic molecules in pancreatic endocrine tumors.
Clin Cancer Res 2007;13:187–196.
[4]...