Background: Unlike familial polyposis coli, where the premalignant nat
ure of adenomatous polyps is well established, the cancer risk in juve
nile polyposis has generally been considered not increased. Methods: T
his study reviews all cases of juvenile polyposis reported in the Engl
ish language to date to assess the occurrence and prognosis of carcino
ma in the gastrointestinal tract. Results: A total of 218 patients met
the inclusion criteria. Mean age at diagnosis was 18.5 years (range:
9 months to 67 years). No gender preference was identified. The most c
ommon presenting symptom was chronic anemia, followed by acute gastroi
ntestinal bleeding, rectal prolapse of polyp, protein-losing enteropat
hy, and intussusception. A family history of juvenile polyposis could
be established in similar to 50% of patients, and associated congenita
l malformations were detected in 15%. Ninety-nine patients underwent 1
38 gastrointestinal operations: 121 colorectal, 12 gastric, and 5 smal
l intestinal procedures. The development of a gastrointestinal carcino
ma was reported in 36 cases (17%). Mean age at diagnosis of carcinoma
was 35.5 years (range: 4-60 years). Most malignancies were located in
the distal colon and rectum, with only one case of gastric and one cas
e of duodenal carcinoma. Tumor stage at diagnosis was usually advanced
, with poor survival figures. Conclusions: This study shows that juven
ile polyposis syndromes carry a more significant risk of carcinoma tha
n generally appreciated. Therefore, more intense endoscopic surveillan
ce may be warranted, and definitive surgical options should often be c
onsidered in these syndromes.