Juvenile polyposis syndrome
Symptoms tend to present in the 20s and include bleeding, diarrhea, and intussusception. The average age at diagnosis is 18.5 years. There is a variant of JPS in infancy that carries similar presenting symptoms, with the addition of macrocephalus and hypotonia. Patients with JPS are at increased risk for colorectal cancer (CRC), with up to 20% developing it by age 35 and over 60% by age 60. JPS is associated with hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome), especially if linked with mutation in SMAD4. The diagnosis of JPS is made if there are more than 5 juvenile polyps in the colorectum, multiple juvenile polyps in other areas of the GI tract, or with any number of juvenile polyps in someone with known family history.
Q85.8 – Other phakomatoses, not elsewhere classified
9273005 – Juvenile polyposis syndrome
Differential Diagnosis & Pitfalls
- Peutz-Jeghers syndrome – Autosomal dominant syndrome associated with mutation in STK11. Associated with hamartomatous polyps in the GI tract, mucocutaneous pigmentation, and increased risk of GI and non-GI cancer.
- Nevoid basal cell carcinoma syndrome – Autosomal dominant syndrome due to mutation in PTCH1 gene. Associated with multiple basal cell carcinomas, palmar / plantar pitting, and macrocephaly. Patients can have several hamartomatous polyps in the stomach.
- Phosphatase and tensin homolog (PTEN) hamartoma tumor syndrome – Includes Cowden syndrome and Bannayan-Riley-Ruvalcaba syndrome (BRRS); associated with mutation in PTEN1 gene. Characterized by macrocephaly, lipomas, vascular abnormalities, and developmental delay.
- Familial adenomatous polyposis (FAP) – Multiple colorectal adenomatous polyps associated with mutation in the APC or MUTYH gene. Polyps may also be found in the upper GI tract. These polyps are histologically different from juvenile polyps.