Serrated polyposis syndrome. Heterogeneous syndrome, variable in type, size, distribution and number of polyps, being more frequent in male smokers with a distal phenotype. Most patients also have adenomatous polyps synchronously. These patients require an organized multidisciplinary evaluation.
Protruded lesions of the colonic or rectal mucosa , which in their endoscopic semiology can simulate non- neoplastic lesions, but on histological examination they present particular characteristics that determine the risk of dysplasia and CRC ( colorectal cancer ).
Summary
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- 1 story
- 2 Patient Management
- 3 Endoscopic Surveillance
- 4 Epidemiology
- 5 Diagnosis
- 6 Conclusions
- 7 sources
History
First described in 1980. It is a syndrome characterized by the presence of numerous serrated polyps, which can be large, with a family history and an exceptionally high risk of CRC ( colorectal cancer ).
The genetic basis remains unknown, so currently the definition remains phenotypic and includes a very heterogeneous group of patients.
The WHO has agreed on the clinical criteria for the clinical diagnosis of SPS (serrated polyposis syndrome), which have been recently updated, and it is considered that one of the following criteria must be met:
- 5 or more serrated polyps proximal to the sigmoid colon (2 of them larger than 10 mm);
- any number of serrated polyps proximal to the sigmoid in a first-degree relative with SPS; O well
- more than 20 serrated polyps distributed throughout the entire colon.
It is a rare disease, with an incidence of 1 every 100,000 inhabitants, although this is probably an underdiagnosed condition.
The risk of CRC ( colorectal cancer ) is not established but has been estimated at up to 70%.
Although it is considered that there is no increased risk of extracolonic tumors, some authors have reported a higher frequency of non-colonic neoplasms, without being able to establish whether there is a true relationship with SPS.
Reported family history of CRC ranges from 0% to 59% of cases. Likewise, families with an autosomal dominant, autosomal recessive or no family history have been described. All of this suggests that SPS encompasses a heterogeneous group of patients that probably correspond to diseases with a different genetic basis.
Patient Management
A serrated polyp photographed by colonoscopy .
It should be recommended that they be included in a program of close endoscopic surveillance. It is currently considered advisable to perform a high-quality annual total colonoscopy , preferably with the use of chromoendoscopy techniques with biological dyes (for example, indigo carmine) or virtual chromoendoscopy (for example, narrow band images) to increase the rate of detection of serrated lesions.
In the event that the disease is not considered controllable by endoscopy, similar to attenuated adenomatous polyposis, a subtotal colectomy with ileorectostomy should be proposed , although this is a controversial aspect.
However, the information known to date on SPS (serrated polyposis syndrome) is scarce, so most of the recommendations are made based on the opinion of experts, and are not supported by scientific evidence.
In this issue of the journal, a retrospective cohort of 23 patients from a single center who meet the definition of SPS based on endoscopies performed between 2005 and 2012 is presented, and their clinical and phenotypic characteristics are analyzed.
It should be noted that the inclusion of the patients was made after the re-evaluation of the endoscopic reports and the anatomopathological review. In this case, 0.08% of the colonoscopies met SPS criteria. In recent prospective cohorts in our setting, up to 0.3% of colonoscopies performed for a fecal occult blood test have been diagnosed with SPS.
Serrated polyps, due to their peculiar characteristics (flat, mucus-covered, preferentially located in the right colon), make them especially difficult to detect. Therefore, it is expected that the introduction of improvements in the quality of endoscopy (high definition, chromoendoscopy) will increase these detection rates in the future. The higher percentage of distal and mixed SPS phenotypes observed may also be overestimated because the right colon is more difficult to evaluate and where most of the undetected polyps and interval cancer are concentrated.
Secondly, the authors identify a high association with the smoking habit , already described previously, and which makes it necessary to consider smoking abstinence within the management of patients with SPS.
Regarding surgical management, a subtotal colectomy with ileorectostomy is currently recommended. However, it is a decision that must be agreed with the patient considering pros and cons. It is possible that a more conservative surgery could be adapted depending on the predominant phenotype of the disease as suggested by the authors (for example, a right hemicolectomy in the case of a proximal phenotype).
Endoscopic surveillance
An annual colonoscopy is recommended, although longitudinal follow-up studies are necessary to assess the usefulness of the proposed strategies and adapt them to the risk of metachronous lesions in each patient phenotype.
Therefore, it is necessary to delve into the clinical characteristics of patients with SPS (serrated polyposis syndrome) in order to classify them into subgroups that help a future molecular diagnosis, identify the real risk of CRC (colorectal cancer), identify epidemiological factors that increase the risk of neoplastic transformation and establish an adequate endoscopic surveillance strategy based on longitudinal follow-up studies. To advance in the knowledge of this disease, the contribution of different groups in its dissemination is essential, as well as the contribution of series of a large number of patients within multicenter studies.
Epidemiology
- It is estimated that they represent between 2 and 9% of colorectal polyps
- 20% of screening colonoscopies present PS in the proximal colon
- Its detection is proposed as a strategy to reduce mortality associated with proximal CRC
Diagnosis
Most cases are asymptomatic. The diagnosis of the lesions is made by VCC (video colonoscopy).
Some strategies to increase your detection rate are:
- colon preparation
- Chromoendoscopy
- High resolution VCC (>410,000 pixels )
- High resolution + magnification (410,000 pixels + zoom between 60 and 100×)
- NBI (narrow band imaging: narrow bandimages) – FICE – I Scan
- confocal endomicroscopy
Conclusions
Serrated polyps represent a heterogeneous group of lesions that have in common at the histological level the sawtooth arrangement of the surface cells of their crypts. In recent years, evidence has shown that its behavior is not always benign as previously thought, presenting the potential for malignancy and progression to CRC following genetic pathways called “serrated pathways of carcinogenesis”, which are still under study and are not known. with precision. This requires that PS must be actively searched for by colonoscopy and completely removed, although due to their flat morphology and pale color they may not be detected in screening or surveillance endoscopy, even more so in patients with inadequate colonic preparation.
