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.

The causes of pyogenic liver abscess has been known as biliary tract disease or intrabadominal infection but the large proportions of the patients has no apparent underlying disorders. Recently colonic mucosal lesions were reported in patients with cryptogenic liver abscess and it has been suggested that colonic mucosal break may play a role in developing liver abscess in otherwise healthy patients. We experienced a patient of severe recurrent liver abscess complicated with endophthalmitis only 3 months after successful treatment of initial cryptogenic liver abscess and a polypoid colon cancer was discovered by chance. It seems prudent to proceed colonoscopic examination in patients with cryptogenic liver abscess especially when it is recurrent.