Management of Pancreatic Cystic Lesions

Thick slab MRCP image showing massive dilatation of the main pancreatic duct

Incidental cystic pancreatic lesions found on 13% of MRI abdomens

• Wide variety of pathology both benign and malignant
• Imaging findings and demographics are the key to diagnosis

Cystic Pancreatic Neoplasms (Four major categories)

1. Serous cystadenoma: Benign (very low malignant potential)
2. Mucinous cystic neoplasm (MCN): Premalignant or malignant
3. Intraductal papillary mucinous neoplasm (IPMN): Malignant potential (Main Duct >> Branch Duct)
4. Unusual cystic neoplasms:
   • Solid pseudopapillary neoplasm (SPN): Low grade malignancy
   • Cystic forms of more common neoplasms (neuroendocrine)

Nonneoplastic Pancreatic Cysts

• Pseudocyst
• Retention cyst
• Lymphoepithelial cyst
• Localized ductectasia

Major Imaging Features Guiding Management

• Number and size of cystic components: Risk of malignancy increases when size ≥ 3 cm
• Septations and solid components: Mural nodule has a 87% Sp and 56% Sn for malignancy
• Main pancreatic duct (MPD) dilatation and communication with the cystic lesion: MPD > 10 mm has a 77% Sp and 67-92% Sn for malignancy

Sendai Criteria

High Risk Stigmata

• Jaundice
• MPD ≥ 10 mm
• Enhancing solid component

Worrisome Features

• Size ≥ 3 cm
• MPD 5-9 mm
• Non-enhancing mural nodules
• Thick enhancing cystic wall
• Lymphadenopathy
• Abrupt Duct Termination

Management

• Any worrisome features present = Endoscopic Ultrasound (EUS) and Cyst aspiration with fluid analysis
• Any high risk stigmata present or suspicious cytology on EUS = Surgical resection
• MCN or SPN = Surgical resection
• Serous cystadenoma
  • 2-3 cm: F/U every 2 years
  • ≥ 4 cm: consider resection
• IPMN:
  • Main duct and combined type: Surgical resection (but depends on location, pt. age/clinical status)
  • Branch duct type = follow if < 3 cm and contains no solid components
    • If < 2cm F/U q1yr; if growth FU q6mo
    • If 2-3 cm F/U q6mo x 2 years, then q1yr
    • Consider EUS (if mucinous then resect)
    • If growth ≥ 3 cm, resect

What the Clinician/Surgeon wants to know

1. Number of cystic lesions
2. Largest cystic lesion
   • Unilocular
   • Multilocular: Microcystic (<2cm) or Macrocystic (> 2cm)
3. Lesion size
4. Lesion location: Head/Body/Tail
5. Septations: None/Thin/Thick (> 2mm)
6. Solid components: Present/Absent
7. Calcifications: None/Coarse/Rim/Central
8. Communication with MPD: Present/Absent
9. Main pancreatic duct diameter: > 5 mm/Not dilated

References

• Gandhi NS and Hecht E. “Adding Value to Clinical Care: Structured Reporting of Pancreatic Pathology”, Workshop Session Presentation, Society of Abdominal Radiology Annual Meeting, 2015
• Tanaka M,Fernández-del Castillo C, Adsay V,et al. International consensus guidelines 2012 for the management of IPMN andMCN of the pancreas. Pancreatology(2012) May-Jun;12(3):183-97
• DewhurstCE, Mortele KJ. Cystic tumors of the pancreas: Imaging and management. RadiolClin N Am 50(2012)467-86
• SahaniDV, Miller JC, and Fernandez C et al. Cystic pancreatic lesions: Classificationand Management. ACR (2009)
• SahaniDV, Kadavigere R, and Saoker A. Cystic Pancreatic Lesions: A SimpleImaging-based Classification System for Guiding Management. Radiographics (2005)25:1471-1484