ABSTRACT
Objective To analyze the value of dynamic enhanced multi-slice spiral computed tomography (MSCT) combined with two-dimensional (2D) curved reconstruction technique in the differentiation of benign and malignant intraductal papillary mucinous neoplasm (IPMN) of pancreas,and compare with magnetic resonance cholangiopancreatography(MRCP).Methods MSCT and MRCP data of a total of 50 patients with IPMNs confirmed by pathology after surgery was retrospectively reviewed.The benign and malignant IPMNs were differentiated based on the presence of mural nodules,main pancreatic duct (MPD) ≥ 10 mm,septum thickness ≥2 mm,calcification,surrounding vascular infiltration,enlarged peripancreatic lymph nodules,distant metastatic lesions and maximal branch duct type IPMN lesions ≥30 mm shown in the images.The sensitivity,specificity and accuracy were calculated and the receiver-operating-characteristics (ROC) analysis were drawn.Area under the curve (AUC) was calculated.Results Mural nodules in MSCT had a sensitivity,specificity,and accuracy of 77.1％ (27/35),80.0％ (12/15) and 78.0％ (39/50) for diagnosing malignant IPMN,respectively;which in MRCP were 77.1％ (27/35),86.7％ (13/15),and 80.0％ (40/50) in comparison.When MPD diameter ≥10 mm was used for diagnose malignancy,MSCT and MRCP had the sensitivity,specificity,and accuracy of 96.3％ (26/27),81.8％ (9/11),92.1％ (35/38),and 96.3％ (26/27),90.9％ (10/11),94.7％ (36/38),respectively.For thick septum ≥2 mm,MSCT and MRCP had the sensitivity,specificity,and accuracy of 4.8.6％ (17/35),93.3％ (14/15),62.0％(31/50),and 51.4％ (18/35),93.3％ (14/15),64.0％ (32/50),respectively.Out of 50 cases,calcifications were detected on MSCT in 6 patients,and 5 of them were pathologically diagnosed as malignant IPMN.MRCP failed to identify calcifications in any of these lesions.For MSCT,the AUC of MPD diameter ≥ 10 mm,mural nodules and thick septum ≥ 2 mm were 0.973 (P =0.000),0.825 (P =0.002) and 0.704(P =0.051),respectively.For MRCP,the AUC of the three factors above were 0.976(P =0.000),0.825(P =0.002),0.722 (P =0.034),respectively.For the predicting of IPMN malignancy,MSCT had an overall sensitivity,specificity,and accuracy of 94.3％ (33/35),73.3％ (11/15) and 88.0％ (44/50),respectively;in comparison,MRCP had values of 94.3％ (33/35),80.0％ (12/15) and 90.0％ (45/50),respectively.Conclusions Presence of mural nodules,MPD ≥10 mm and thick septum ≥2 mm on MSCT combined with 2D curved reconstruction or MRCP have a high value for predicting the malignancy of IPMN.The values of MSCT and MRCP were basically consistent in the differentiation of benign and malignant IPMN.MSCT can be used as the preferred examination for diagnosing IPMN in the primary hospitals without MR equipment.
ABSTRACT
BACKGROUND: Surgical resection is the treatment of choice of intraductal papillary mucinous neoplasm (IPMN) of the pancreas. However, the benefit of clearing resection margin is still controversial. METHODS: We reviewed 281 surgically resected cases of IPMN. The recurrences were compared according to the histologic grade (benign or borderline IPMN, malignant noninvasive IPMN, invasive carcinoma) and size (pancreatic intraepithelial neoplasia, PanIN, less than 0.5 cm in the long axis; and IPMN, greater than or equal to 0.5 cm) of the residual lesions at the resection margin. RESULTS: Sixty cases (21.4%) were invasive carcinoma, and 221 (78.6%) noninvasive cases included 87 (31.0%) benign, 107 (38.1%) borderline and 11 (3.9%) malignant noninvasive IPMN cases. In noninvasive IPMN, increased recurrence in patients with five or more years of follow-up was only related to the involvement of resection margin by severe dysplasia. The recurrence of invasive carcinoma was high (27.3%) even when the resection margin was clear, and was not related to the grade or size of residual tumors at the resection margin. CONCLUSIONS: Invasiveness is a strong risk factor for recurrence in IPMN regardless of the status of the resection margin. However, in noninvasive IPMN, histologic grading of residual lesions at the resection margin predicts local recurrence.