Les polypes gastriques: pathologie et génétique

Gastric polyps: a 10-year analysis of 18,496 upper endoscopies

Background/aims

Gastric polyps (GPs) are usually asymptomatic lesions of the upper gastrointestinal tract observed in 1–3% of esophagogastroduodenoscopies (EGD). Most GPs are benign. The aim of this study was to precise the frequency of different types of gastric polyps in our population, and to analyze their possible association with other factors.

Materials and methods

A total of 18,496 consecutive patients undergoing EGD over a 10-year period (between 2007 and 2018) in a tertiary hospital were retrospectively reviewed. Eighty-six patients diagnosed with gastric polyps were analysed. Demographics, medical history of the patients, and indication for gastroscopy were collected. Morphological, histological characteristics of polyps, and therapeutic management data were also collected.

Results

GPs were found in 86 out of 18,496 (0.46%) reviewed EGD, corresponding to a total of 141 polyps. There were 64 female (74.4%) and 22 male patients (25.6%) with a sex ratio (M/F) of 0.34. The average age was 58.1 years. One hundred and forty one polyps were included, and histopathology was obtained on 127 GPs. The most common location was the fundus (59.6%) and 48.9% were smaller than 5 mm. The polyp was unique in 75.6% of cases. According to Paris classification, 80% of the polyps were sessile (Is). Hyperplastic polyps were the most common (55.9%), followed by sporadic fundic gland polyps observed in 23 patients (18.1%), 7 (5.5%) were adenomas and 4 (3.1%) were neuroendocrine tumors type 1. The following factors were associated with hyperplastic polyps: anemia (p = 0.022), single polyp (p = 0.025) and size ≥ 5 mm (p = 0.048). Comparing hyperplastic polyps’ biopsies to resected polyps, no difference was found in the evolutionary profile of the 2 groups. A size less than 10 mm (p = 0.013) was associated with fundic gland polyps. Sixty polyps (47.2%) were treated by cold forceps, 19 (15%) treated by a mucosal resection and 15 (11.8%) with diathermic snare. Five procedural bleeding incidents were observed (3.9%). Only the use of anticoagulant treatment was associated with a high bleeding risk (p = 0.005). The comparative histological study between specimens of biopsied GPs and endoscopic polypectomy led to an overall agreement of 95.3%.

Conclusion

In our study, the GPs frequency was 0.36%. Hyperplastic polyps and fundic gland are the most common in our country. The high frequency of Helicobacter pylori infection in our patients and in our area may explain the high frequency of HP.

[Gastric adenoma of pyloric type associated with familial adenomatous polyposis: A rare histological type not to be overlooked]

We report here two cases of gastric adenomas of pyloric type diagnosed during the follow-up of familial adenomatous polyposis (FAP). This rare histological lesion has been only recently described in this particular context and its clinical and pathological spectrum remains to be evaluated. Our two cases were very different in their clinical and endoscopic presentation. In the first patient, the lesion was diagnosed late during the evolution of FAP; it was very large and protruded above the adjacent mucosa; because of its large size, its treatment proved to be difficult. In the second patient, the lesion was discovered incidentally in gastric biopsies, early in the course of FAP. Both lesions presented the characteristic morphological and immunohistochemical features of pyloric adenoma, including the expression of MUC6. Both showed evidence of dysplasia, including high-grade dysplasia in the largest lesion. Pyloric adenoma belongs to the spectrum of gastric polyps associated with FAP; its prognosis and evolution remain to be evaluated.

[Pseudomalignant endoscopic appearance in hyperplastic polyp at esophagogastric junction: case report]

Hyperplastic polyps are by far the most common benign tumors in the stomach larger than 5mm. Although the malignant potential of hyperplastic gastric polyps was originally denied, a low risk for carcinomatous conversion is now recognized. Its has been recommended that all gastric polyps of 5mm or more in diameter have to be removed. We present here the case of a large hyperplastic gastric polyp located at the esophagogastric junction with endoscopic malignant appearance. The description of its endoscopic and histological characteristics gives us the opportunity to discuss the difficulty of endoscopic diagnosis in the case of gastric polyps and to remind their prognosis.