Branch-duct intraductal papillary mucinous neoplasm (IPMN): Are cyst volumetry and other novel imaging features able to improve malignancy prediction compared to well-established resection criteria?

Abstract

Objectives Current guidelines base the management of intraductal papillary mucinous neoplasms (IPMN) on several well-established resection criteria (RC), including cyst size. However, malignancy may occur in small cysts. Since branch-duct (BD) IPMN are not perfect spheres, volumetric and morphologic analysis might better correlate with mucin production and grade of dysplasia. Nonetheless, their role in malignancy (high-grade dysplasia/invasive cancer) prediction has been poorly investigated. Previous studies evaluating RC also included patients with solid-mass-forming pancreatic cancer (PC), which may affect the RC yield. This study aimed to assess the role of volume, morphology, and other well-established RC in malignancy prediction in patients with BD- and mixed-type IPMN after excluding solid masses. Methods Retrospective ethical review-board-approved study of 106 patients (2008–2019) with histopathological diagnosis of BD- and mixed-type IPMN (without solid masses) and preoperative MRI available. Standard imaging and clinical features were collected, and the novel imaging features cyst-volume and elongation value [EV = 1 − (width/length)] calculated on T2-weighted images. Logistic regression analysis was performed. Statistical significance set at two-tails, p < 0.05. Results Neither volume (odds ratio (OR) = 1.01, 95% CI: 0.99–1.02, p = 0.12) nor EV (OR = 0.38, 95% CI: 0.02–5.93, p = 0.49) was associated with malignancy. Contrast-enhancing mural nodules (MN), main pancreatic duct (MPD) ≥ 5 mm, and elevated carbohydrate antigen (CA) 19-9 serum levels (> 37 μmol/L) were associated with malignancy (MN OR: 4.32, 95% CI: 1.18–15.76, p = 0.02; MPD ≥ 5 mm OR: 4.2, 95% CI: 1.34–13.1, p = 0.01; CA19-9 OR: 6.72; 95% CI: 1.89 – 23.89, p = 0.003). Conclusions Volume and elongation value cannot predict malignancy in BD- and/or mixed-type IPMN. Mural nodules, MPD ≥ 5 mm and elevated CA19-9 serum levels are associated with higher malignancy risk even after the exclusion of solid masses. Key Points • Novel and well-established resection criteria for IPMN have been evaluated after excluding solid masses. • BD-IPMN volume and elongation value cannot predict malignancy. • Main pancreatic duct ≥ 5 mm, mural nodules, and elevated carbohydrate antigen 19-9 levels are associated with malignancy.

A Comparison of Single Dimension and Volume Measurements in the Risk Stratification of Pancreatic Cystic Lesions

“…This is despite the confirmation with elongation value data that most of these lesions were not spherical. The only variables in the study which were associated with advanced neoplasia were the presence of contrast-enhancing mural nodules, a diameter of MPD ≥ 5 mm, and serum CA 19-9 level > 37 [ 50 ].…”

Modern aspects of the management of pancreatic intraductal papillary mucinous neoplasms: a narrative review

“…Mural nodules, the main pancreatic duct more than 5 mm in diameter and elevated carbohydrate antigen 19-9, also called cancer antigen 19-9 (CA19-9), serum levels are related to malignancy [37].…”

Can our experience with surveillance for inherited pancreatic cancer help to identify early pancreatic cancer in the general population?

“…Consensus guidelines for individuals at risk (IAR) are developed by the international Cancer of the Pancreas Screening (CAPS) Consortium [ 1 ]. This group of IAR is better suited compared to other risk groups such as patients with chronic [ 2 ] or autoimmune [ 3 ] pancreatitis or patients with IPMN [ 4 ] that all are at risk to develop pancreatic cancer. The ground truth being surgical pathology demonstrating high-grade dysplasia or T1a invasive cancer as a reference.…”