Reappraisal of surgical indication of mucinous cystic neoplasm of the pancreas: a systematic review and meta-analysis

Background: Although mucinous cystic neoplasm (MCN) have a lower risk of high-grade dysplasia (HGD) or invasive carcinoma (IC) than branch duct type intraductal papillary mucinous neoplasm, aggressive surgical management is generally recommended. To optimize treatment strategies, the prevalence of HGD or IC in resected MCNs, as well as preoperative predictors, should be explored. These findings will inform patient selection for surgery and may reduce unnecessary interventions. Methods: This study systematically reviewed eligible studies that included information regarding the grade of dysplasia. Summary data, including carbohydrate antigen 19-9, cyst size, mural nodules, and cyst wall thickening, of patients with resected MCN were extracted and analyzed. Results: A total of 53 studies involving 4,384 cases of resected MCN were selected in search of PubMed, Embase, and Cochrane databases. The pooled rate of HGD or IC among the resected MCN was 17.0%, with more recent studies showing a decreasing trend. Patients with HGD or IC had larger cysts than those with low-grade dysplasia (P < 0.001). A cyst size threshold of 65 mm was identified as the optimal value for differentiating MCN with HGD or IC from those with low-grade dysplasia (Youden index: 0.44). Also, elevated carbohydrate antigen 19-9 (> 37 U/mL), presence of mural nodules, and cyst wall thickening were associated with the diagnosis of HGD or IC. Conclusion: Given the low rates of HGD or IC in resected MCNs and the identification of specific preoperative risk factors, a more targeted surgical approach based on risk stratification is warranted.