Metastatic Rectal Adenocarcinoma in Familial Adenomatous Polyposis: A Case of Socioeconomic Factors Influencing Surveillance Endoscopy

Familial adenomatous polyposis (FAP) is a rare syndrome caused by adenomatous polyposis coli (APC) gene mutation resulting in the development of hundreds of adenomatous colorectal polyps. The disease process usually manifests fully by the second decade of life. Total colectomy or restorative proctocolectomy is often required to prevent the development of colorectal adenocarcinoma. Routine surveillance following surgery is critical for the early detection of polyps or malignancy. We present a rare case of a 31-year-old male with a history of FAP status post total proctocolectomy with ileal pouch-anal anastomosis (IPAA) who presented with acute exacerbation of lower back pain and new-onset lower extremity paresthesia. Imaging demonstrated an aggressive T12 vertebral body lesion. Pathology following laminectomy demonstrated metastatic adenocarcinoma. Subsequent pouchoscopy revealed a distal 1.5-cm pedunculated lesion arising from remnant rectal tissue with pathology confirming moderately differentiated rectal adenocarcinoma. This patient underwent a prophylactic proctocolectomy 20 years prior to this admission but was lost to follow-up prior to any endoscopic evaluations. Despite postoperative surveillance guidelines and patient counseling, follow-up and recommended endoscopic evaluation are often inadequate. This case examines potential socioeconomic factors influencing the completion of surveillance endoscopy and also represents an opportunity to incorporate education and provide resources to patients with FAP to improve surveillance examinations and mitigate the development of preventable malignancies.