Pancreatic Cystic Lesions- Imaging Based Classification and Proposal for Therapeutic Guidelines

Abstract

Introduction: Cystic lesions of the pancreas are increasingly being recognized due to the widespread use of cross-sectional imaging. Therefore, it is important to characterize cystic neoplasms and to distinguish cystic neoplasms of the pancreas from pseudocysts.

Aim: To propose an classification system of the cystic pancreatic lesions that is based on the morphologic features of the lesion This system can be helpful in characterizing lesions, narrowing the differential diagnosis, and making decisions regarding the treatment of affected patients.

Materials and Methods: The study comprised 56 individuals (27 men and 29 women) with cystic pancreatic lesions as their final diagnosis. The following materials were used: Ultrasonic equipment with 3.5 and 7 MHz linear, convex and biopsical transducers, MDCT investigations were done with a 16-slice scanner. During the pancreatic and portal venous phases of contrast enhancement, images are taken . The “Chiba” needles 18, 20, 22, 23G, automatique aspiration system, methods of guiding the interventional procedures.

Results and Discussion:  At least two cuts imaging survey modalities, including as US, CT, or MRI, were performed on all 56 patients in this investigation. The most common preoperative diagnostic examination was US scan - 56 patients (100% ), MDCT studies have been conducted in 49 (87.50%) and MRI in 13(23.21%). More than half of patients surveyed (37) have underwent some type of interventional procedure: 25-FNA and 29-FNAB, as part of the examination. 34 patients of all 56 patients because of histological evidence of malignancy after the FNAB for cystic lesions of the pancreas were operated. Comparing the diagnostic results of US examination with those of MDCT examination and histological verification we estimated the power of the diagnostic imaging methods for cystic lesions of the pancreas. The specificity of 68.75%, sensitivity 79.48%, accuracy 75.00%, positive predictive value 86.11% and negative predictive value 55% were obtained. The power increased after applying invasive procedures with immunohistochemical analysis of CEA and P- 53. In patients with clear symptoms and / or clear imaging features of malignant or premalignant cystic neoplasm, the need for surgery was confirmed by histological verification in 34 (60.71%) of cases.

Conclusions: Cystic mucinous tumours of the pancreas might have been discovered and correct operational procedures might have been performed with fewer diagnostic exams if the proposed methodology had been employed.