A patient undergoes colonoscopy and is found to have more than 100 colonic polyps. Genetic testing reveals a germline APC mutation. This patient is at highest risk for which extra-colonic manifestation?
- A Hepatoblastoma
- B Desmoid tumors ✓
- C Medulloblastoma
- D Osteosarcoma
Correct answer: B. Desmoid tumors
Explanation
Familial adenomatous polyposis (FAP) due to APC mutation is associated with numerous extra-colonic manifestations. Desmoid tumors (aggressive fibromatoses) occur in 10-20% of FAP patients, particularly those with mutations distal to codon 1310 or at codon 1444, and represent a major cause of morbidity and mortality in post-colectomy FAP patients. Gardner syndrome (FAP variant) specifically features desmoids, osteomas, and epidermoid cysts. Medulloblastoma occurs in Turcot syndrome (FAP variant) but is far less common.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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