Affiliations: [a] Department of Ultrasound, Zhongshan Hospital, Fudan University, Shanghai, China
| [b] Department of Pancreatic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
Correspondence:
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Corresponding authors: Prof. Yi Dong, Department of Ultrasound, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China. Tel.: 86 (0)21 64041990 2474; Fax: 86 (0)21 64220319; E-mail: dong.yi@zs-hospital.sh.cn and Prof. Wen-Hui Lou, Department of Pancreatic Surgery, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China. Tel.: 86 (0)21 64041990 2474; Fax: 86 (0)21 64220319; E-mail: lou.wenhui@zs-hospital.sh.cn.
Note: [1] Grant Support: Supported by National Natural Science Foundation of China (Grant No. 82071942); Supported by Clinical Research Plan of SHDC (Grant No. SHDC2020CR4060); Supported by Shanghai Municipal Science and Technology Medical Guidance Project (Grant No. 18411967200); Supported by Shanghai Pujiang Program (Grant No. 2020PJD008).
Note: [2] These authors contributed equally.
Abstract: AIM:Preoperative suspicion of malignancy in nonfunctioning pancreatic neuroendocrine tumors (pNETs) is mostly based on tumor size. We retrospectively analyzed the contrast enhanced ultrasound (CEUS) features of a series of histopathologically proved nonfunctioning pNETs. METHODS:In this retrospective study, 37 surgery and histologically proved nonfunctioning pNETs were included. All pNETs lesions were incidentally detected by transabdominal ultrasound. B mode ultrasound (BMUS) and CEUS features were reviewed and analyzed. 52 histopathologically proved pancreatic ductal adenocarcinoma (PDACs) lesions were included as a control group. RESULTS:All nonfunctioning pNETs patients showed no typical clinical symptoms. No significant differences were observed in size, echogenicity or internal color flow imaging signal between pNETs and PDAC patients (P > 0.05). Most of nonfunctioning pNETs showed a well-defined tumor margin. The presence of pancreatic duct dilatation was less frequently observed in nonfunctioning pNETs patients (P < 0.05). After injection of ultrasound contrast agents, homogeneous enhancement was more commonly observed in nonfunctioning pNETs group (P < 0.05). During arterial phase of CEUS, most of nonfunctioning pNETs were hyper- or isoenhanced (32/37, 86.5%), whereas most of PDACs were hypoenhanced (34/52, 65.4%) (P < 0.05). Nonenhanced necrosis area was more commonly detected in PDACs (P = 0.012). CONCLUSIONS:CEUS features are helpful for preoperative non-invasive differential diagnosis of nonfunctioning pNETs, assisting further clinical decision-making process.
