The RET/PTC rearrangement in papillary thyroid carcinoma activates which signalling pathway, and is particularly associated with which epidemiological trigger?
- A BRAF V600E mutation; hereditary MEN2 syndrome
- B RAS mutation; autoimmune thyroiditis (Hashimoto's)
- C RET/PTC rearrangement activating MAPK pathway; post-radiation exposure (Chernobyl) ✓
- D PAX8-PPARγ rearrangement; dietary iodine deficiency
Correct answer: C. RET/PTC rearrangement activating MAPK pathway; post-radiation exposure (Chernobyl)
Explanation
RET/PTC rearrangements activate the MAPK (RAS-RAF-MEK-ERK) signalling pathway and are classically associated with radiation-induced papillary thyroid carcinoma, as seen in children exposed to fallout from the Chernobyl nuclear accident. BRAF V600E is the most common somatic mutation in sporadic PTC. PAX8-PPARγ is associated with follicular thyroid carcinoma. RAS mutations occur in follicular adenoma/carcinoma and FVPTC.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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