Purpose: The purpose of this study was to retrospectively evaluate diagnostic accuracy of cystic lesions of the pancreas in order to determine if less aggressive surgical treatment might be safe and therefore warranted.
Methods: A retrospective cohort study was conducted in 232 patients with either observed or resected cystic lesions of the pancreas referred for evaluation and treatment to the University Medical Center Freiburg, Germany, between 2001 and 2011.
Results: Most patients had MRI or CT for preoperative imaging (90.6 %). Preoperatively, benign pseudocysts (BPC) were diagnosed in 84 (36.2 %) patients and intraductal papillary mucinous neoplasm (IPMN) in 59 (25.2 %) patients, whereas serous cyst adenoma, mucinous cystic neoplasm (MCN), solid pseudopapillary tumors (SPPTs), and neuroendocrine tumors (NETs) were less common. In 43 % of patients, the preoperative diagnosis concurred with the postoperative diagnosis. The preoperative diagnosis was accurate in BPC, less so in IPMN, and inaccurate in MCN, NET, and SPPT. However, prediction of tumor biology was accurate; only 11 % of the lesions regarded as benign turned out to be malignant after resection, and no patient without resection developed malignancy at a median follow-up of 8 months. Subsequently, 89 % of diagnosed benign tumors had indeed benign pathology.
Conclusions: The prediction of biology is often correct, whereas specific diagnosis is often wrong. A considerable amount of benign lesions are treated more aggressively than warranted if malignancy is suspected prior to surgery. Parenchyma-sparing techniques might be an option, but prospective multicenter studies need to follow. Experienced pancreatic radiologists can improve accuracy of preoperative biology.
Keywords: IPMN; Pancreatic cystic lesions; Parenchyma sparing surgery; Preoperative imaging.