In familial adenomatous polyposis (FAP), which extraintestinal manifestation is pathognomonic and detectable even before colonic polyps develop, aiding early family screening?
- A Congenital hypertrophy of the retinal pigment epithelium (CHRPE) ✓
- B Desmoid tumours of the mesentery
- C Osteomas of the jaw
- D Thyroid papillary carcinoma
Correct answer: A. Congenital hypertrophy of the retinal pigment epithelium (CHRPE)
Explanation
Congenital hypertrophy of the retinal pigment epithelium (CHRPE) presents as flat, pigmented retinal lesions detectable by ophthalmoscopy. CHRPE is present at birth, occurs in approximately 70–80% of FAP patients with specific APC mutations (codons 463–1387), and appears before colonic polyps develop in childhood. It is therefore a useful early marker for family screening. Desmoid tumours, osteomas, and thyroid carcinoma are features of Gardner syndrome (a variant of FAP) but are not detectable before colonic disease and are not considered pathognomonic.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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