In cholangiocarcinoma, serum CA 19-9 and CEA have limited sensitivity. Which additional biomarker, measured in bile or serum, has been studied as a diagnostic adjunct for intrahepatic cholangiocarcinoma?
- A AFP (alpha-fetoprotein)
- B IDH1/IDH2 mutations in circulating tumour DNA ✓
- C IgG4
- D PSA
Correct answer: B. IDH1/IDH2 mutations in circulating tumour DNA
Explanation
Intrahepatic cholangiocarcinoma (iCCA) harbours IDH1 and IDH2 mutations in approximately 15–20% of cases. Detection of IDH1/IDH2 mutations in liquid biopsy (circulating tumour DNA) has emerging diagnostic and therapeutic value. IDH inhibitors (ivosidenib for IDH1-mutated iCCA) are approved in the second-line setting per ClarIDHy trial. IgG4 elevation suggests autoimmune pancreatitis/IgG4-related sclerosing cholangitis, a PSC mimic.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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