Who should a patient with a possible intraductal papillary mucinous neoplasm (IPMN) be referred to after an MRI of the abdomen?

Management of Patients with Possible Intraductal Papillary Mucinous Neoplasm (IPMN)

Patients with a possible IPMN identified on abdominal MRI should be referred to a pancreatic surgeon for evaluation, with concurrent referral to a gastroenterologist for potential endoscopic ultrasound assessment if worrisome features are present. 1

Initial Evaluation and Risk Stratification

• MRI with MRCP is the preferred imaging modality for comprehensive evaluation of pancreatic cysts due to its superior sensitivity (96.8%) and specificity (90.8%) in distinguishing IPMN from other cystic pancreatic lesions 1
• Risk stratification should be performed based on the following features:
  • High-risk stigmata: obstructive jaundice with cyst in pancreatic head, enhancing solid component within cyst, main pancreatic duct (MPD) ≥10 mm 1, 2
  • Worrisome features: MPD dilation 5-9 mm, cyst size ≥3 cm, mural nodules, growth rate ≥5 mm/year 1, 3

Referral Algorithm Based on IPMN Type and Risk Features

Main Duct IPMN (MD-IPMN) or Mixed-Type IPMN

• These patients should be immediately referred to a pancreatic surgeon due to high malignancy risk (56-91%) 3, 4
• Surgical resection is universally recommended for patients who are fit for surgery 1

Branch Duct IPMN (BD-IPMN) with High-Risk Stigmata

• Direct referral to a pancreatic surgeon is indicated 1, 2
• Surgical resection is typically recommended if the patient is fit for surgery 1

Branch Duct IPMN with Worrisome Features

• Dual referral to both:
  • Gastroenterologist for EUS-FNA evaluation 1, 2
  • Pancreatic surgeon for surgical consultation 1
• EUS allows high-resolution imaging and tissue sampling, with cytological evaluation identifying 30% more cancers than imaging features alone 2

Branch Duct IPMN without High-Risk Features or Worrisome Features

• For cysts <3 cm without worrisome features: Referral to gastroenterologist for surveillance planning 1, 3
• For cysts ≥3 cm even without other worrisome features: Consider surgical consultation due to increased malignancy risk 1, 5

Special Considerations

• Age and comorbidities should be factored into the referral decision, as patients with Charlson-age comorbidity index ≥7 have an 11-fold risk of comorbidity-related death within 3 years 1
• Surgical strategy should be individualized based on the type of surgical resection required, patient's age, comorbidities, and preferences 1
• Lifelong surveillance is recommended for all IPMNs, even after surgical resection, as the risk of developing new lesions or progression of existing lesions increases over time 1, 3

Common Pitfalls to Avoid

• Do not rely solely on cyst size for risk assessment; consider multiple risk factors including growth rate, mural nodules, and MPD dilation 3, 2
• Do not use the same follow-up protocol for all types of IPMNs; tailor the approach based on IPMN subtype and risk factors 1, 3
• Do not neglect the need for lifelong surveillance, even after partial pancreatectomy for IPMN, as there is risk of new lesions in the remnant pancreas 1
• Do not delay referral for MD-IPMN or mixed-type IPMN as these have high malignancy potential and generally require surgical intervention 1, 4