No abstract available.
Adenomatous Polyps*

Epithelial gastric polyps can be categorized as hyperplastic or adenomatous polyps. Hyperplastic polyps are predominant, comprising 75 to 90% of gastric polyps. It has been generally accepted that adenomatous gastric polyps exhibit malignant change. However, potential of malignant transformation of hyperplastic gastric polyps was originally denied and have been rarely reported, the incidence varying from 1.5 to 2.1%. The size and the associated dysplasia of polyps seem to be important in transformation to gastric carcinoma. Most of the reported cases of hyperplastic gastric polyps with transformation to adenocarcinoma were histopathologically well differentiated. We report a rare case of moderately differentiated adenocarcinoma arising in a hyperplastic polyp on the greater curvature of the midbody in the stomach with a brief review of the literatures.
Adenocarcinoma* ; Adenomatous Polyps ; Incidence ; Polyps* ; Stomach*

Epithelial colon polyps are largely divided into hyperplastic and adenomatous polyps. Adenomatous polyps are premalignant lesions, whereas hyperplastic polyps are regarded as benign lesions. However, this histological classification has been blurred, as cases of malignant changes in hyperplastic polyposis, mixed hyperplastic adenomatous polyps (MHAPs), and serrated adenomas in the colon have been reported. Rare cases of MHAP have been reported, and are mainly found at the proximal colon with a relatively large size. MHAPs seem to be an intermediate stage of the hyperplastic polyp-adenoma sequence or a collision tumor. Here, we report on a case of a single polyp in the rectum diagnosed with a MHAP combined with an invasive adenocarcinoma.
Adenocarcinoma ; Adenoma ; Adenomatous Polyps ; Colon ; Polyps ; Rectum

Adenomatous polyps have been well known to be premalignant, but it is still controversial how to treat and follow them up. Up to date, endoscopic resection has been the choice of treatment, particularly exceeding 2 cm, though there is no concensus on the indications for the excision of hyperplastic polyps. The incidence of malignant tissue found in hyperplastic polyps has been reported to be less than 3%, which is considerably lower than the incidence of greater than 6% reported in adenomas. There have been few reports of hyperplastic polyps in which malignant changes developed during endoscopic surveillance. We report a case of hyperplastic gastric polyp with intramucosal, well-differentiated adenocarcinoma with reviewing references.
Adenocarcinoma* ; Adenoma ; Adenomatous Polyps ; Incidence ; Polyps*

No abstract available.
Adenoma* ; Colorectal Neoplasms ; Polyps ; Colonoscopy ; Adenomatous Polyps

No abstract available.
Adenomatous Polyposis Coli* ; Colectomy* ; Humans ; Polyps*

Until recently, colorectal polyps were classified predominantly as hyperplastic or adenomatous. While adenomatous polyps are well-characterized precursor lesions of adenocarcinomas, hyperplastic polyps have been considered as benign lesion. However, some hyperplastic polyps with serrated morphology of the crypts have been recognized to have distinctive features and these polyps were termed 'serrated adenomas'. Recent data show that sessile serrated adenomas (SSA) might be the precursors of serrated colonic cancers, underlining the necessity of identifying them. SSA is approximately 3% of all polyps, commonly appears as flat or sessile and yellowish due to mucus production. In the pathogenesis of SSA, progression to high grade dysplasia or early invasive carcinoma may be associated with serrated neoplasia pathway different from adenoma-carcinoma sequence. We report a case with a colon polyp diagnosed as sessile serrated adenoma with high grade dysplasia after endoscopic submucosal dissection.
Adenocarcinoma ; Adenoma ; Adenomatous Polyps ; Colon ; Colonic Neoplasms ; Mucus ; Polyps

BACKGROUND/AIMS: Colonoscopy is considered to be the gold standard for detecting adenomatous polyps. Polyps are missed during colonoscopic examination at a rate that varies from 6% to 27%. The adenoma miss rate affects colonoscopic surveillance intervals and procedural quality. We aimed to assess the adenoma miss rate and the variables affecting the rate using same-day, quality-adjusted, back-to-back colonoscopies. METHODS: This prospective study was performed at a single institution and included 149 patients. Two consecutive same-day colonoscopies were performed by two experienced endoscopists. The adenoma miss rates and variables affecting the missed adenomas, including polyp characteristics and procedure times, were evaluated. RESULTS: The miss rates of polyps, adenomas, and advanced adenomas were 16.8%, 17%, and 5.4%, respectively. The smaller polyps and increased number of polyps detected during the first colonoscopy were more likely to be missed. A longer insertion time during the colonoscopy was correlated with an increased adenoma detection rate. CONCLUSIONS: There was a significant miss rate in the detection of colonic adenomas even in quality-adjusted, back-to-back colonoscopies. The adenoma miss rate can be reduced with a sufficient observation time during colonoscopic insertion. The development of specific technological methods to reduce the adenoma miss rate is necessary.
Adenoma ; Adenomatous Polyps ; Colon ; Colonoscopy ; Humans ; Polyps ; Prospective Studies

Epithelial gastric polyps can be categorized as being either hyperplastic or adenomatous. Hyperplastic polyps accounts for 75~90% of gastric polyps. In contrast to the adenomatous polyps, the potential of a malignant transformation of hyperplastic polyps was originally believed to be quite low (an incidence of 1.5~2.1%), which is considerably lower than that of an adenoma of the stomach. Most of reported cases of a hyperplastic gastric polyp with a transformation to adenocarcinoma were well differentiated histopathologically. There are few reports of a hyperplastic polyp in which malignant changes developed during the endoscopic surveillance. We report a rare case of a 1.2 cm sized moderately differentiated adenocarcinoma arising in a hyperplastic polyp on the cardia in the stomach with a brief review of the relevant literature.
Adenocarcinoma* ; Adenoma ; Adenomatous Polyps ; Cardia ; Incidence ; Polyps* ; Stomach

Gastric polyps can be categorized as hyperplastic or adenomatous. Hyperplastic gastric polyps account for 28~77% of gastric polyps. Adenomatous polyps are recommended for removal due to their premalignant potential. However, there is no consensus on treatment and endoscopic surveillance of hyperplastic gastric polyps. The incidence of malignant neoplasms found in hyperplastic polyps has been reported to be about 2.1%; most of the reported cases of hyperplastic gastric polyps with malignant transformation were histologically well differentiated. We report a rare case of a gastric hyperplastic polyp with a signet ring cell carcinoma, with a review of the literature.
Adenomatous Polyps ; Carcinoma, Signet Ring Cell ; Consensus ; Incidence ; Polyps