Clinicoradiological features of resected serous cystic neoplasms according to morphological subtype and preoperative tentative diagnosis: can radiological characteristics distinguish serous cystic neoplasms from other lesions?

Purpose Serous cystic neoplasm (SCN) of the pancreas is considered benign in most cases. However, some SCN patients undergo surgical resection because lesions could not be differentiated preoperatively. This study evaluated causes of resection for SCN, investigated clinical and radiological features of surgically resected SCNs, and compared characteristics of SCNs diagnosed accurately and those misdiagnosed. Methods One hundred patients, who underwent surgery for pancreatic cystic tumors with pathological confirmation of SCN between 2000 and 2014 were retrospectively analyzed. Results The mean patient age was 52.9 years, 67 (67%) were female, and most lesions (72%) were located in the pancreatic body or tail. Fifty-one (51%) pathologically confirmed SCNs were preoperatively diagnosed as non-SCNs. Patients underwent surgery due to uncertain diagnosis (58%) or symptomatology (18%). According to radiological examination, most lesions were macrocystic (85%), exhibited septation (58%), or were enhancing lesions (48%). Compared with preoperatively diagnosed non-SCNs, accurately diagnosed SCNs exhibited septation (75.5% vs. 41.2%, P = 0.001) and central scar (36.7% vs. 11.8%, P = 0.003) more frequently in radiological examinations. In terms of macrocystic tumors (n = 85), most parameters did not differentiate preoperative diagnoses, although lesions accurately diagnosed as SCN exhibited septation more frequently than those preoperatively misdiagnosed as mucinous cystic neoplasm or intraductal papillary mucinous neoplasm (70.7% vs. 38.9% vs. 33.3%, respectively, P = 0.009). Conclusion It is difficult to accurately distinguish macrocystic SCNs from other cystic tumors using conventional radiological methods. For more accurate diagnosis, new biomarkers and/or other diagnostic modalities are needed and warrant further investigation.