Pathogenesis and Management of Serrated Polyps: Current Status and Future Directions

Hyperplastic or serrated polyps were once believed to have little to no clinical significance. A subset of these polyps are now considered to be precursors to colorectal cancers (CRC) in the serrated pathway that may account for at least 15% of all tumors. The serrated pathway is distinct from the two other CRC pathways and involves an epigenetic hypermethylation mechanism of CpG islands within promoter regions of tumor suppressor genes. This process results in the formation of CpG island methylator phenotype tumors. Serrated polyps are divided into hyperplastic polyps, sessile serrated adenomas/polyps (SSA/Ps), and traditional serrated adenomas (TSAs). The SSA/P and the TSA have the potential for dysplasia and subsequent malignant transformation. The SSA/Ps are more common and are more likely to be flat than TSAs. Their flat morphology may make them difficult to detect and thus explain the variation in detection rates among endoscopists. Challenges for endoscopists also include the difficulty in pathological interpretation as well surveillance of these lesions. Furthermore, serrated polyps may be inadequately resected by endoscopists. Thus, it is not surprising that the serrated pathway has been linked with interval cancers. This review will provide the physician or clinician with the knowledge to manage patients with serrated polyps.

Caracterización clínica y genética de las poliposis intestinales hereditarias / Clinics and genetic characteristics in hereditary colon polyposis

Se denomina pólipo intestinal a una lesión visible elevada o tumor que se proyecta desde la superficie epitelial al lumen visceral. En relación al número, presencia de antecedentes familiares, manifestaciones extraintestinales y estudios genéticos es que se constituyen diversas poliposis intestinales. Si bien, las poliposis intestinales se manifiestan en general en la edad adulta, existen manifestaciones que pueden hacer sospechar la presencia de un síndrome poliposico hereditario en la infancia. Además en una proporción considerable estas poliposis presentan manifestaciones extraintestinales, tanto benignas como tumores en otros órganos. Es por esto, que una alta tasa de sospecha, en particular frente a pacientes con antecedentes familiares, puede conducir a un diagnóstico y tratamiento oportuno, además de considerar a la familia como potenciales pacientes e ingresar al grupo familiar a un registro de tumores hereditarios. Diversas técnicas de biología molecular han permitido la identificación de las mutaciones que son heredadas en estas enfermedades, permitiendo realizar conductas preventivas al saber el riesgo de cada persona en una familia afectada. El objetivo de esta revisión, es caracterizar las distintas poliposis intestinales, en cuanto a sus manifestaciones clínicas, clasificaciones, estudio genético y enfrentamiento multidisciplinario.

Polyps are solid or tumoral elevated lesions that arise from the intestinal epithelium so that they become visible in the intestinal epithelium so that they become visible in the intestinal lumen. Information regarding familial history, number, extraintestinal manifestations and genetic studies of polyps, assemble different types of intestinal polyposis. Generally, clinical manifestations occur in adult patients, although in children there are several signs that should make the physician suspect a hereditary polyposis syndrome. In addition it is important to know extraintestinal manifestations which are mostly benign but tumors may be present in other organs too. Bearing in mind that high clínical suspicion of hereditary polyposis syndrome especially if familial history is present, provides early diagnosis and appropriate treatment for the patient and eventually for the family members that could be affected, entering that family in a registry of hereditary tumors. Molecular biology has created different techniques to identify the presence of hereditary mutations that are specific for intestinal polyposis. Acknowledgment of these mutations establishes risks groups allowing adequate prevention strategies. The objective of this revision is to characterize and different types of intestinal polyposis, according to clinical manifestations, classification, genetic study and multidisciplinary approach.