University of Miami Miller School of Medicine Boca Raton, FL
Alejandro Rodriguez, MD, MS1, Shyam C. Vedantam, DO2, Camilo J. Acosta, MD2, Sean Bhalla, MD2, Jodie A. Barkin, MD, FACG3 1University of Miami/Jackson Memorial Hospital, Hialeah, FL; 2University of Miami Miller School of Medicine, Miami, FL; 3University of Miami Miller School of Medicine, Boca Raton, FL
Introduction: Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer-related deaths. While distant metastases commonly involve the liver, peritoneum, and lungs, colon metastasis is rare. Our aim is to present 2 cases of PDAC colon metastasis and review the literature.
Case Description/Methods: Case 1: A 69y/o woman with PDAC diagnosed at an outside hospital was referred for repeat colonoscopy after chemotherapy. At diagnosis, she had a locally invasive mass in the distal pancreatic body, CA 19-9 of 2100, and an initial colonoscopy showing a rectal mass with biopsy indicating PDAC. She presented to our institution and was started on FOLFIRINOX to downstage her disease. She had a marked decrease in CA 19-9 after 12 treatment cycles. However, CT demonstrated diffuse thickening of the colon suggestive of colitis, most severe in the rectum. She underwent repeat colonoscopy, notable for irregular narrowing in the rectum, with biopsies showing microscopic foci of PDAC within colonic mucosa (Fig 1AB). Chemotherapy was reinitiated, and surgery was deferred.
Case 2: An 82y/o man with metastatic PDAC of the tail (to the liver and left adrenal gland) presented with a 1-month history of GI-obstructive symptoms. CT abdomen and pelvis with oral contrast demonstrated a narrowed luminal caliber at the mid-sigmoid colon. Flexible sigmoidoscopy showed a severe intrinsic stricture at 15 cm from the anal verge with abnormal mucosa (Fig 1C-F). Biopsies confirmed metastatic PDAC to the colon. He underwent colonic stenting but eventually perished due to other complications of his hospital course.
Discussion: PDAC solitary metastasis to the colon without direct invasion from the pancreas or known peritoneal disease is a rare entity. Colon metastases may lead to malignant stricture and present with large bowel obstruction, with colonic stenting as a palliative option. Additionally, synchronous colonic lesions in PDAC may pose a diagnostic challenge, as subtle imaging findings may represent malignancy. Our literature review yielded 22 reports of 23 additional cases of PDAC with metastasis to the colon (mean age 70, 72% men). Our 2 cases expand the literature by demonstrating the utility of colonoscopy to diagnose distant metastatic disease without direct invasion. Palliative stenting can be used in cases of complete obstruction. Although rare, PDAC metastasis to the colon can occur, and high clinical suspicion is necessary to confirm the diagnosis as it can alter staging and management of these complex patients.
Figure: Figure 1: A) Case 1 - CTAP w contrast demonstrating diffuse colonic wall thickening, most severe in segment extending to rectum. B) Case 1 - Colonoscopy showing irregular, nodular and erythematous mucosa with narrowing measuring 1 cm x 1.5 cm in rectum 7cm from anal verge. Biopsy demonstrated microscopic focus of adenocarcinoma involving colorectal mucosa. C) Case 2 - Flexible sigmoidoscopy view of severe intrinsic stenosis 15 cm proximal to the anus. It measured 7 mm (inner diameter). Abnormal villous/infiltrative appearing tissue involving the area of stenosis circumferentially. Biopsies demonstrated PDAC. D) Case 2 - Endoscopic view after placement of 25mm x 9cm wall flex stent traversing malignant stricture. Immediately upon placement, excellent drainage of liquid stool and contrast media from upstream colon was observed. E) Case 2 - Fluoroscopy demonstrating malignant stricture approximately 2 cm in length with contrast in colon proximal to mucosal narrowing. F) Case 2 - Fluoroscopy after placement of WallFlex stent traversing the area of stenosis. Good positioning upstream and downstream of stenosis.
Disclosures:
Alejandro Rodriguez indicated no relevant financial relationships.
Shyam Vedantam indicated no relevant financial relationships.
Camilo Acosta indicated no relevant financial relationships.
Sean Bhalla indicated no relevant financial relationships.
Alejandro Rodriguez, MD, MS1, Shyam C. Vedantam, DO2, Camilo J. Acosta, MD2, Sean Bhalla, MD2, Jodie A. Barkin, MD, FACG3. P3573 - Pancreatic Cancer Solitary Metastasis to Colon is a Rare Entity: Case Reports With Review of the Literature, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.
