Which IPMN genetic feature is associated with IPMN?

• A. KRAS mutation, low amylase, high CEA
• B. KRAS/GNAS/BRAF mutation, variable amylase, high CEA
• C. No mutation, high amylase, high CEA
• D. CTNNB1 mutation, low amylase, low CEA

Answer: (B)

IPMN has a distinctive genetic and cyst-fluid profile. Activating mutations in KRAS are common in pancreatic neoplasms, and GNAS mutations are particularly characteristic of IPMN, helping to distinguish it from other mucinous cysts. Some IPMNs can also harbor a BRAF mutation, reflecting the spectrum of genetic changes that can occur in these lesions. Cyst-fluid CEA tends to be high in mucinous cysts like IPMN, indicating the mucinous nature of the lesion, while amylase in the cyst fluid can vary because not all IPMNs show the same degree of communication with the pancreatic duct.

Putting this together, a pattern that includes KRAS and GNAS mutations (with the possible presence of a BRAF mutation) and a high CEA level, with variable amylase, best matches the typical IPMN profile.