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
Ryan Schwope

 

Cystic Pancreatic Neoplasms (Four major categories)

 

    1. Serous cystadenoma: Benign (very low malignant potential)

 

    1. Mucinous cystic neoplasm (MCN): Premalignant or malignant

 

    1. Intraductal papillary mucinous neoplasm (IPMN): Malignant potential (Main Duct >> Branch Duct)

 

    1. 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

 

    1. Largest cystic lesion
        • Unilocular
        • Multilocular: Microcystic ( 2cm)

 

    1. Lesion size

 

    1. Lesion location: Head/Body/Tail

 

    1. Septations: None/Thin/Thick (> 2mm)

 

    1. Solid components: Present/Absent

 

    1. Calcifications: None/Coarse/Rim/Central

 

    1. Communication with MPD: Present/Absent

 

    1. 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