IDDF2020-ABS-0041 Pancreatic neuroendocrine tumors: correlation between the sonographic features and the pathological tumor grade. (18th November 2020) - Huang, Jingzhi
Abstract : Background: It is confirmed that patients' prognosis of pancreatic neuroendocrine tumors (pNETs) were different according to different pathological grades. Imagings may predict tumor grades. We intended to analyse the value of contrast-enhanced ultrasound (CEUS) in the pathological classification of pNETs. Methods: Eighty-six pNETs patients who underwent CEUS before pathologic diagnosis were retrospectively reviewed. Ultrasonographic features and enhancement pattern in each phase were analyzed among the three pathologic grades of pNETs. Results: Eighty-six pNETs included 45 G1(52.3%), 29 G2 (33.7%), 12 G3 (14.0%). 48.9% (22/45) G1 tumors were less than 2 cm, while 93.1% (27/29) G2 and 100% (12/12) G3 were larger than 2 cm (G1 vs. G2, p < 0.001; G1 vs. G3, p = 0.001). 58.3% (7/12) G3 tumors had pancreatic duct dilatation and 41.7% (5/12) G3 had hepatic metastasis, which were more common than G1 tumors with both only 4.4% (2/45) had pancreatic duct dilatation or hepatic metastasis ( p < 0.001, p = 0.002). On CEUS, G1 tumors ((figure 1A, 1B ) showed homogeneously hyper-enhancement in the early phase) more often menifested hyper- or iso- enhancement in the early phase (0–30s) than G2 ((figure 2A, 2B ) showed homogeneously iso-enhancement in the early phase) and G3 ((figure 3A, 3B ) showed inhomogeneously iso-enhancement in the early phase) tumors ( p =0.006, p <0.001). Besides, the incidence rate of hyper-enhancement in the early phase was higher in G2 tumors than G3 tumors (p=0.009). While in the late phase (31–120s), the incidence rate of iso-enhancement in G1 tumor ((figure 1C ) showed iso-enhancement in the late phase) was higher than G2 ((figure 2C ) showed hypo-enhancement in the late phase) and G3 ((figure 3C ) showed hypo-enhancement in the late phase) tumors (p=0.001, p <0.001). Heterogeneous enhancement and non-enhanced area appeared more often in G2 tumor than G1 tumor (p=0.007, p=0.002). Conclusions: Sonographic features, such as tumor size, pancreatic duct dilatation or hepatic metastasis as well as enhancement pattern in each phase may help to predict different pathologic grade of pNETs.