[Branch duct intraductal papillary mucinous neoplasm - surgical approach]

[Pancreatic cystic space-occupying lesions-Diagnostics, treatment and follow-up care : Current recommendations taking the current German S3 guidelines on pancreatic cancer into account]

Due to their increased detection pancreatic cystic space-occupying lesions are becoming increasingly relevant in the clinical routine and represent a morphologically and biologically heterogeneous and thus clinically demanding as well as potentially (pre)malignant entity. As a result, recommendations for the diagnostics and treatment of pancreatic cystic tumors have now been incorporated into the current German S3 guidelines on pancreatic cancer. The diagnostics of pancreatic cystic space-occupying lesions are based on the following three elements: collection of relevant clinical information, performance of high-resolution imaging procedures and if diagnostic uncertainty persists, puncture diagnostics. Differentiated diagnostics are of essential importance as these represent the basis for an adequate treatment decision. Pancreatic cystic lesions with a relevant risk of malignant transformation, e.g., main duct intraductal papillary mucinous neoplasms (IPMN), followed by mucinous cystic neoplasms (MCN), solid pseudopapillary neoplasms (SPN) and generally pancreatic cystic lesions with risk factors independent of the entity, should be resected, whereas a differentiated and individualized approach is necessary, especially for branch-duct IPMNs. The serous cystic neoplasms (SCN) have no malignant potential and do not require any treatment if they are asymptomatic. Important principles in surgery of pancreatic cancer, such as adequate surgical resection taking oncological standards into account and standardized appropriate histopathological processing of the specimens as well as intraoperative frozen section analysis also play an important role in pancreatic cystic space-occupying lesions. An annual follow-up seems to be meaningful, especially for IPMNs.

Management and outcomes of intraductal papillary mucinous neoplasms

Background

This study evaluated the outcome and survival of patients with radiologically suspected intraductal papillary mucinous neoplasms (IPMNs).

Methods

IPMN management was reviewed according to Fukuoka risk factors and IPMN localization, differentiating main‐duct (MD), mixed‐type (MT) and branch‐duct (BD) IPMNs. Perioperative results were compared with those of patients undergoing resection of pancreatic ductal adenocarcinoma (PDAC) over the same interval (2010–2014). Overall (OS) and disease‐specific (DSS) survival rates were calculated and subgroups compared.

Results

Of 142 patients with IPMNs, 26 had MD‐IPMN, eight had MT‐IPMN and 108 had BD‐IPMN. Some 74 per cent of patients with MD‐ and MT‐IPMN were managed by primary resection, whereas this was used in only 27·8 per cent of those with BD‐IPMN. The risk of secondary resection and malignant transformation for BD‐IPMNs smaller than 20 mm was 8 and 2 per cent respectively during follow‐up. Pancreatic head resection of IPMNs was associated with an increased risk of postoperative pancreatic fistula grade B/C compared with resection of PDAC (12 of 33 (36 per cent) versus 41 of 221 (18·6 per cent) respectively; P = 0·010), and greater morbidity and mortality (Clavien–Dindo grade III: 15 of 33 (45 per cent) versus 56 of 221 (25·3 per cent) respectively; grade IV: 1 (3 per cent) versus 7 (3·2 per cent); grade V: 2 (6 per cent) versus 2 (0·9 per cent); P = 0·008). Five‐year OS and DSS rates in patients with MD‐IPMN were worse than those for MT‐ and BD‐IPMN (OS: 44, 86 and 97·4 per cent respectively, P < 0·001; DSS: 60, 100 and 98·6 per cent; P < 0·001). Patients with invasive IPMN had worse OS and DSS rates than those with non‐invasive dysplasia (OS: IPMN‐carcinoma (10 patients) 33 per cent, high‐grade dysplasia 100 per cent, intermediate‐grade dysplasia 63 per cent, low grade‐dysplasia 100 per cent, P < 0·001; DSS: IPMN‐carcinoma 43 per cent, all grades of dysplasia 100 per cent, P < 0·001). Patients with high‐risk stigmata had poorer survival than those without risk factors (OS: high‐risk stigmata (35 patients) 55 per cent, worrisome features (31) 95 per cent, no risk factors (76) 100 per cent, P < 0·001; DSS: 71, 100 and 100 per cent respectively, P < 0·001).

Conclusion

The risk of malignant transformation was very low for BD‐IPMNs, but the development of high‐risk stigmata was associated with disease‐specific mortality. Patients with IPMN had greater morbidity after resection than those having resection of PDAC.