What are the characteristics of Branch-type Intraductal Papillary Mucinous Neoplasm (IPMN)?

From the Guidelines

Branch-type Intraductal Papillary Mucinous Neoplasm (IPMN) characteristics include the presence of a cyst size ≥30 mm, a growth rate ≥5 mm/year, and increased levels of serum CA 19.9 (>37 U/mL) as relative indications for surgical resection 1.

Key Characteristics

• Cyst size: ≥30 mm is considered a relative indication for surgery, with a positive predictive value for malignancy of 27-33% 1
• Growth rate: ≥5 mm/year is a relative indication for surgery, with a 20-fold higher risk of malignant progression if the size increases >5 mm/year or has a total growth of 10 mm 1
• Serum CA 19.9 levels: >37 U/mL is a relative indication for surgery, with a positive predictive value of 74.0% and accuracy of 81.7% to identify patients with invasive IPMN 1
• Mural nodules: ≥5 mm is an absolute indication for surgery, while <5 mm is a relative indication 1
• Main pancreatic duct (MPD) dilatation: ≥10 mm is an absolute indication for surgery, while 5-9.9 mm is a relative indication 1

Diagnostic Approaches

• Imaging: high-resolution CT, endoscopic ultrasound (EUS), and magnetic resonance cholangiopancreatography (MRCP) are used to evaluate IPMN 1
• Endoscopic retrograde cholangiopancreaticography (ERCP): may reveal dilated pancreatic ducts or nodules in the cyst wall 1
• Tumor markers: increased serum levels of carcinoembryonic antigen (CEA) or cancer antigen 19-9 (CA19-9) may be detected in patients with an IPMN with an associated invasive carcinoma 1

From the Research

Characteristics of Branch-type Intraductal Papillary Mucinous Neoplasm (IPMN)

• The branch-type IPMN is a subtype of intraductal papillary mucinous neoplasm (IPMN) that arises in the branch ducts of the pancreas 2, 3, 4.
• Studies have shown that branch-type IPMNs can be malignant, with a reported malignancy rate of 18% to 22% 2, 4.
• The characteristics of branch-type IPMNs that are associated with malignancy include:
  • Tumor size > 2 cm 3
  • Presence of a mural nodule 3, 4, 5
  • Thick wall or nodules 4
  • Tumor diameter ≥ 30 mm 4
  • Main pancreatic duct (MPD) ≥ 5 mm 5
  • Elevated carbohydrate antigen (CA) 19-9 serum levels 5
• The diagnosis of branch-type IPMNs is typically made using magnetic resonance imaging (MRI) 6.
• The management of branch-type IPMNs depends on the tumor size, cyst growth rate, solid components, main duct dilatation, high-grade dysplasia in cytology, the presence of symptoms, and CA 19-9 serum level 6.
• Surgery is recommended for branch-type IPMNs that are suspected to be malignant or have high-risk features, while surveillance is recommended for those that are suspected to be benign 3, 6.