Table 1 Differences in clinicopathological characteristics and treatment between JPS and FAP

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.