Abstract
Intestinal spirochetosis (IS) is an infectious gastrointestinal disease caused by Brachyspira bacteria. We detail an exceedingly rare case of IS with concomitant invasive colorectal adenocarcinoma (CRC) in a 58-year-old man presenting with abdominal discomfort and fever. Colonoscopic evaluation revealed abnormal-appearing, nodular cecal mucosa and a 35 mm rectosigmoid mass. Histopathology confirmed IS infection and CRC. Our case report is the first to detail IS diagnosed concurrently with colorectal cancer. It highlights the necessity of a high index of suspicion for IS in patients presenting with abdominal discomfort and endoscopic evidence of irregular nodular mucosa, particularly in the setting of suspected CRC. It further details potential pathophysiologic links between IS and colorectal malignancy.