Rapidly growing colon adenocarcinoma and its differential

Abstract

Among cancers in the United States, colorectal cancer is the third most commonly diagnosed, and the second leading cause of death. Most colon cancers are thought to develop from adenomatous polyps through the adenoma-carcinoma sequence, which emphasizes the importance of screening colonoscopies for early detection and obliteration of precancerous polyps. As the adenoma-carcinoma sequence is estimated to take 10-15 years to occur, current guidelines recommend screening colonoscopies every 10 years, beginning at the age of 50, for average-risk individuals. For those that have adhered to screening guidelines and experienced a consistently negative detection of polyps, screening is no longer recommended after the age of 75 and recommended against after the age of 85. Currently, there are no guidelines on the management of patients with inadequate bowel preparation for colonoscopy, which has been associated with a significant adenoma miss rate. This report illustrates the management of a high-grade invasive adenocarcinoma of the right colon that was identified in an 88-year-old patient who had received a colonoscopy 7 years earlier with no evidence of polyp growth. This was either an unusual case of rapid growth or an unfortunate case of a previously missed adenoma (carcinoma). It invites an evaluation of the current guidelines and their implications.