Association of colon adenocarcinoma in situ in polyp with subsequent colon cancer: A population-based retrospective study.

e15605 Background: Adenocarcinoma in situ (pTis) of the colon is defined as malignant cells confined within epithelium or mucosa. Since pTis is not invasive, polypectomy alone is usually adequate, especially if resection margins are cancer-free. We performed a population-based study to investigate the association of intrapolyp pTis and subsequent colon cancer. Methods: We queried the SEER database (1975-2017) for patients with pTis in adenoma. We further filtered patients with subsequent colon cancers. Standard incidence ratios (SIRs) were used to evaluate the excess risk of developing subsequent colon cancers comparing to the general population. Difference between patients who did or did not develop colon cancer were analyzed using Chi-square test. Results: A total of 15164 patients with pTis were identified. Among them, 736 (4.85%) patients developed subsequent colon cancer. Age ≥70 years, pTis in villous adenoma, polyp in hepatic flexure, splenic flexure, transverse colon, descending colon, and diagnosis year before 2000 were associated with increased risk of developing subsequent colon malignancy (all p< 0.05). Polypectomy comparing to colectomy (total, subtotal or partial) is associated with a higher rate of developing subsequent colon cancers ( p < 0.05). In patients with intrapolyp pTis, observation/expectation (O/E) of developing colon cancers are elevated to 4.76, 1.84, 1.66, and 1.28 within one year, 1-5 year, 5-10 year, and after ten years, respectively (all p< 0.05). O/E for the male and female is 1.80 and 1.63 (both p< 0.05); for the white and black is 1.64 and 2.21(both p< 0.05). Conclusions: Subsequent colon cancers developed in 4.85% of pTis patients. Excess risk of developing subsequent colon cancers is highest in the first year, and declines with time but persists beyond ten years. Male and black have the highest excess risk. Factors like older age, villous adenoma, location from hepatic flexure to descending colon, and polypectomy are associated with developing subsequent colon cancers.

Low-grade Appendiceal Mucinous Neoplasm (Appendiceal Villous Adenoma) with Cystic Fibrosis: A Case Report

Cystic fibrosis (CF) is an autosomal dominant disease characterized by the dysfunction of exocrine secretory glands resulting from a mutation in the transmembrane regulator protein (CFTR) gene. As life expectancy increases in patients with cystic fibrosis secondary to advances in treatment, advanced age malignancies secondary to cystic fibrosis emerge. Especially, the frequency of gastrointestinal system malignancies and colon cancers increases with aging. Appendiceal tumors are a rare entity and constitute less than 1% of gastrointestinal tumors. We presented a villous adenoma encountered in an 18-year-old male patient with CF accompanied by clinical and radiological findings. Our case is the first reported appendiceal tumor that emerged in patients with cystic fibrosis.

Endoscopic submucosal tunnel dissection for a giant adenoma of the cecum (case report)

Endoscopic removal of giant adenomas of the cecum is associated with high risk of perforation and conversion to laparoscopic procedure. Endoscopic submucosal dissection for cecal adenomas had technical limitations due to the adjacent ileocecal valve and appendix opening, perpendicular operating angle. Case presentation of the possibility of successful removal of a large laterally spreading cecal adenoma by the method of endoscopic submucosal tunnel dissection (ESTD) never been described before for this tumor site and size. Patient 54 years old, an LST-G adenoma (5 cm in diameter, according to Kudo – IIIL, according to Sano – II) was detected in the dome of the cecum during colonoscopy. ESTD. The postoperative period without any unfavorable events; the patient was discharged on the 5th day after surgery. The morphological conclusion: tubulo-villous adenoma with moderate epithelial dysplasia, R0. ESTD is suitable for cecal giant adenomas.