Intraductal papillary mucinous tumor of pancreas (IPMT)

• Most common cystic pancreatic neoplasm 
• Arise from epithelial cells of main duct or side branches  
• Produces large amount of mucin 
• 4 histological types: dysplasia, borderline, carcinoma in situ, IPMT with invasive cancer 
• Based on location: main duct type, branch duct type or mixed type  
• Diffuse or segmental duct dilatation  
• Mixed type shows diffuse and segmental duct dilatation 
• Solid nodular protrusions or masses accompanying suggest malignancy 
• Main duct lesions more likely to turn malignant and hence needs surgical resection 
• Branch type < 3 cm in size needs only serial follow up in asymptomatic patients 

Fukuoka guidelines for treatment and follow up of IPMT 

• Worrisome features: cyst ≥3 cm, enhancing mural nodules <5 mm, thick enhancing cyst wall, 5-9 mm caliber of main pancreatic duct, abrupt change in caliber of main pancreatic duct with upstream atrophy, lymphadenopathy, rapid cyst growth rate >5 mm/2 years 
• High risk features: jaundice in a patient with cystic lesion of pancreatic head, enhanced mural nodule ≥5 mm and/or main pancreatic calibre ≥10 mm 
• These patients have to undergo resection without further testing 

• Fluid aspirate gives clue: high amylase favors pseudocyst. Mucinous neoplasms have high carcinoembryogenic antigen