[Is accurate preoperative assessment of pancreatic cystic lesions possible?]

Cystic lesions of the pancreas (CLP) are of different origin and behaviour. Mucinous lesions with the risk of invasive cancer represent an important subgroup. The key point in differential diagnosis of CLP is to distinguish malignant and benign lesions and also correct indication for surgery in order to minimize the impact of serious complications after resection. Different and unsatisfying predictive values of each of the examinations make proper diagnosis challenging. We focused on overall diagnostic accuracy of preoperative imaging and analytic studies. We studied the accuracy of distinguishing between non-neoplastic vs. neoplastic and bening vs. malignant lesions.

We retrospectively analyzed all of the patients (N=72) with CLP (median of age 58 years, range 22-79) recommended for surgery. CT, EUS, ERCP, MRCP findings, cytology and aspirate analysis were used to establish preoperative diagnosis. Finally, preoperative diagnoses were compared with postoperative pathological findings to establish overall accuracy of preoperative assessment.

During 5 years, 72 patients underwent resection for CLP. We performed 66 (92%) resection and 6 (8%) palliative procedures with 32% morbidity and 7% of one hospital stay mortality. All the patients were examined by CT and EUS. FNA was performed in 44 (61%) patients. Cytology was evaluable in 39 (88%) cases. ERCP was done in 40 (55%) patients. Pathology revealed non-neoplastic CLP in 25 (35%) and neoplastic lesions in 47 (65%) specimens. Mucinous lesions accounted for 25%. Malignant or potentially malignant CLP were found in 37 (51%) patients. Sensitivity, specificity and diagnostic accuracy of preoperative diagnosis for distinguishing between inflammatory and neoplastic, and benign and malignant was 100%, 46%, 85% and 61%, 61%, 44%, respectively.

Correct and accurate preoperative assessment of CLP remains challenging. Despite the wide range of diagnostic modalities, the definitive preoperative identification of malignant or high-risk CLP is inaccurate. Because of this, a significant portion of the patients undergo pancreatic resection for benign or inflammatory lesions that are not potentially life-threatening. Possible serious complications after pancreatic surgery are the main reason for precise selection of patients with cystic affections recommended for surgery.