Hyperplastic Polyposis Syndrome Identified with a BRAF Mutation

Rare Isolated Duodenal Hamartomatous Polyp in an Elderly Patient

BACKGROUND Hamartomatous polyps represent rare sporadic lesions, characterized by fibrous stroma, vascular infiltration, and dilation of mucous glands. The lesions present in a bimodal fashion in adults as well as children from 1 to 7 years old, and are often diagnosed during endoscopic procedures. Specifically, solitary Peutz-Jeghers represents a type of hamartoma that has similar histologic features to typical Peutz-Jeghers syndrome. Hamartomatous polyps represent disorganized tissue growth and can bear relationships with genetic syndromes classified as hamartomatous polyposis syndromes. A number of these syndromes, such as Peutz-Jeghers and Cowden syndrome, can demonstrate an increased risk of malignancy. A variety of symptoms, or no symptoms at all, can accompany these polyps, such as abdominal discomfort, bowel obstruction, gastrointestinal bleeding, or intussusception in severe cases. Histologically, these polyps appear similar to Peutz-Jeghers syndrome growths; however, they lack extraintestinal manifestations. Given fairly low risk of development into malignancy, patients have a good prognosis if presenting with a solitary hamartomatous polyp. There is limited data regarding screening guidelines for this patient population. CASE REPORT Here, we present a rare case of a 73-year-old woman who had a history of anemia and status post endoscopic evaluation and was diagnosed with a benign hamartomatous polyp (juvenile-like), histologically consistent with tubulovillous adenoma. CONCLUSIONS Differentiating sporadic polyps from syndromic polyps is important, as sporadic polyps have a benign course, while those associated with a syndrome have an increased lifetime malignancy risk.

Ulcerative colitis with inflammatory polyposis in a teenage boy: A case report

Ulcerative colitis in addition to inflammatory polyposis is common. The benign sequel of ulcerative colitis can sometimes mimic colorectal carcinoma. This report describes a rare case of inflammatory polyposis with hundreds of inflammatory polyps in ulcerative colitis which was not easy to distinguish from other polyposis syndromes. A 16-year-old Chinese male suffering from ulcerative colitis for 6 mo underwent colonoscopy, and hundreds of polyps were observed in the sigmoid, causing colonic stenosis. The polyps were restricted to the sigmoid. Although rectal inflammation was detected, no polyps were found in the rectum. A diagnosis of inflammatory polyposis and ulcerative colitis was made. The patient underwent total colectomy and ileal pouch anal anastomosis. The patient recovered well and was discharged on postoperative day 8. Endoscopic surveillance after surgery is crucial as ulcerative colitis with polyposis is a risk factor for colorectal cancer. Recognition of polyposis requires clinical, endoscopic and histopathologic correlation, and helps with chemoprophylaxis of colorectal cancer, as the drugs used postoperatively for colorectal cancer, ulcerative colitis and polyposis are different.

Lineage tracing reveals multipotent stem cells maintain human adenomas and the pattern of clonal expansion in tumor evolution

The genetic and morphological development of colorectal cancer is a paradigm for tumorigenesis. However, the dynamics of clonal evolution underpinning carcinogenesis remain poorly understood. Here we identify multipotential stem cells within human colorectal adenomas and use methylation patterns of nonexpressed genes to characterize clonal evolution. Numerous individual crypts from six colonic adenomas and a hyperplastic polyp were microdissected and characterized for genetic lesions. Clones deficient in cytochrome c oxidase (CCO(-)) were identified by histochemical staining followed by mtDNA sequencing. Topographical maps of clone locations were constructed using a combination of these data. Multilineage differentiation within clones was demonstrated by immunofluorescence. Methylation patterns of adenomatous crypts were determined by clonal bisulphite sequencing; methylation pattern diversity was compared with a mathematical model to infer to clonal dynamics. Individual adenomatous crypts were clonal for mtDNA mutations and contained both mucin-secreting and neuroendocrine cells, demonstrating that the crypt contained a multipotent stem cell. The intracrypt methylation pattern was consistent with the crypts containing multiple competing stem cells. Adenomas were epigenetically diverse populations, suggesting that they were relatively mitotically old populations. Intratumor clones typically showed less diversity in methylation pattern than the tumor as a whole. Mathematical modeling suggested that recent clonal sweeps encompassing the whole adenoma had not occurred. Adenomatous crypts within human tumors contain actively dividing stem cells. Adenomas appeared to be relatively mitotically old populations, pocketed with occasional newly generated subclones that were the result of recent rapid clonal expansion. Relative stasis and occasional rapid subclone growth may characterize colorectal tumorigenesis.