The characteristics and outcome of intraductal papillary mucinous neoplasm of the pancreas: an observational study

Background Intraductal papillary mucinous neoplasms (IPMNs) are pancreatic cystic lesions with variable risk for malignant transformation. This observational study assessed the long-term natural history of IPMNs, focusing on risk stratification based on imaging and histological features. Methods We retrospectively reviewed 93 patients with IPMN confirmed by MRI and endoscopic ultrasound (EUS) or both. All patients had a minimum follow-up of 5 years. Demographic, clinical, imaging, procedural, and outcome data were collected. IPMN characteristics including cyst size, duct size, duct involvement, and location were evaluated at baseline. The primary outcome was progression to high-grade dysplasia or invasive carcinoma. Secondary outcomes included the need for surgery, cyst progression, and IPMN-related mortality. Results The cohort included 93 patients (65.6% female, mean age 70.9 ± 9.9 years). The majority (92.5%) had branch duct IPMN. The mean cyst size was 1.53 ± 1.57 cm, and the duct size was 2.69 ± 1.79 mm. High-grade dysplasia was found in 9.7%. Surgical resection was significantly associated with cyst size >2.6 cm ( P = 0.031), duct dilation >5.3 mm ( P = 0.004), and main/mixed duct involvement ( P < 0.001). Additionally, cyst wall thickening (60%) and mural nodule (67%) were significantly associated with surgical resection. One patient progressed to invasive carcinoma. No IPMN-related deaths were reported. Conclusion IPMNs evaluated and monitored with MRI/EUS demonstrate indolent behavior over extended follow-up. Surgical resection should be considered based on duct type, cyst size, and presence of dysplasia. Long-term surveillance remains essential for appropriate risk stratification.