|Clinical presentation||Multiple juvenile polyps throughout the gastrointestinal tract. The lifetime cancer risk is 10–50%.||Early onset of hundreds to thousands of polyps throughout the colorectum. The lifetime cancer risk is 100% by age 50.|
|Endoscopic appearance||The polyps vary in size, shape and number. Typical: pedunculated, strawberry shape, 5~100 polyps.||Classical: 100-thousands polyps,|
Attenuated: < 100 polyps.
|Pathological findings||Hamartomatous polyps.||Adenomatous polyps.|
|Extracolonic lesions||Gastric cancer, small intestine polyp, pancreas cancer, hereditary hemorrhagic telangiectasia (HHT)||CHRPE, epidermoid cysts, osteoma, desmoid tumor, hepatoblastoma, supernumerary teeth, thyroid cancer, brain tumor|
|Genetic investigations||Autosomal dominant, about 50–60% had germline SMAD4 or BMPR1A mutations||Autosomal dominant, about 80% had germline APC mutation.|
|Treatment||Most could be treated by polypectomy. Colectomy is rarely needed.||Most require TC + IRA or TPC + IPAA.|