Polyps of the gastrointestinal tract are very common lesions and most frequently sporadic in nature. Some polyp subtypes are associated with rare hereditary polyposis syndromes, including juvenile polyposis syndrome, Peutz-Jeghers syndrome, and Cowden syndrome. However, many sporadic benign lesions of the gastrointestinal tract can mimic some of these syndromic hamartomatous polyps. The role of the surgical pathologist is to raise the possibility of a hereditary condition in case of suggestive polyp histology and to look for clinical information to support the suspected diagnosis. In this review, the clinical presentation and the pathology associated with these rare hamartomatous polyposis syndromes are discussed in an attempt to provide pathologists clues in suggesting one such syndrome on the basis of histologic findings and clinical context. Identification of affected individuals is important because of the increased gastrointestinal and other malignancies. Recently, new adenomatous polyposis syndromes have been discovered, expanding the genetic causes of patient diagnosed with multiple colonic adenomas. By being aware of the clinical phenotype and the tumor spectrum associated with gastrointestinal polyposis syndromes, surgical pathologists can play a critical role in recommending genetic counseling when suspicious of such a diagnosis. This may lead to the identification of a genetic cause and appropriate surveillance of affected family members to screen for associated malignancies.