Imaging findings of pancreatic multiple neuroendocrine tumor: A study of 12 cases

Abstract

Objective To investigate the imaging features in CT/MR of pancreatic neuroendocrine tumors(PNETs)with multiple lesions and further deepen the understanding of this disease. Methods A retrospective review of 12 PNETs patients' radiological data with pancreatic tumors' numbers ≥2 and confirmed by surgery or fine needle aspiration biopsy in Changhai Hospital were conducted. Five cases underwent pancreatic CT plain and enhanced scan, 2 cases underwent MRI plain and enhanced scan, and 5 cases underwent both CT and MRI scan. Results There were totally 46 lesions in 12 patients. There were 29(63.0%) lesions located in the pancreatic head and neck, and 17(37.0%) lesions located in body and tail of pancreas. The sizes of the lesions ranged from 0.8 to 9.5 cm, and the median size was 2.9 cm. Forty-four(95.7%) of the tumors was round or oval, and 2(4.3%) was lobulated; 44(95.7%) mass solid and 2(4.3%) was cystic. CT plain scan detected punctate, crescent or nodular calcification in 8(17.4%) lesions; enhanced scan found 42 lesions(91.4%) were markedly enhanced in the arterial phase, 2 lesions (4.3%) were markedly enhanced in the pancreatic phase; 2 lesions (4.3%) were slightly enhanced and the degree of enhancement was lower than that of the normal pancreas. Four cases (33.3%) had dilatation of pancreatic duct and/or the bile duct, 4 cases (33.3%) had distant organ metastasis, 2 cases (16.7%) had lymph node metastasis, and 3 cases (25.0%) had vascular invasion. Conclusions PNETs can be multiple and vary in the size. Most of the lesions are round or oval solid lesions and the malignant signs for organ metastasis can be found occasionally. In dynamic enhanced scanning, the obvious enhancement of the solid portion in the tumor and the higher enhancement degree than that of normal pancreas is the main characteristic. Key words: Pancreas; Neuroendocrine tumors; Tomography, X-ray; Magnetic resonance imaging