S1810 The Great Pretender: Painless Jaundice Caused by a Non-Hepatobiliary Source

Abstract

INTRODUCTION: Painless jaundice is a known sign of obstruction from pathologies within the hepatobiliary system. Proliferation of epithelial cells may form a rare tumor known as a cholangiocarcinoma. Colorectal cancer (CRC) may metastasize to the liver parenchyma but there is no prior report of a common bile duct (CBD) tumor leading to the discovery of CRC. We present a case of obstructive jaundice which was initially thought be cholangiocarcinoma based on Computerized Tomography (CT) imaging and Endoscopic retrograde cholangiopancreatography (ERCP), but found to be hilar metastasis from an undiscovered CRC. CASE DESCRIPTION/METHODS: A 61 year-old man with no known medical history presented with complaints of jaundice, nausea, vomiting, dark urine, and right upper abdominal pain for two weeks. He denied fever, itching, weight loss, constipation or diarrhea. He was a tobacco user and had four tattoos. He denied alcohol, intravenous or other drug use. He had no recent use of acetaminophen or herbal medicine. He had no recent travel, exposure to ill contacts, history of hepatitis or risky sexual practices. His vitals were normal on presentation. On general examination the patient was an elderly man with scleral icterus but other systems, including the abdomen, were unremarkable. CT Abdomen revealed a porta hepatis mass at the CBD, concerning for cholangiocarcinoma. There were also multiple focal areas of the liver, involving the right lobe extending into segment 4 worrisome for additional large areas of metastatic cholangiocarcinoma. He was admitted for further work up. ERCP was performed, revealing a tumor extruding from the CBD. The CBD mass and a hepatic mass were biopsied. A biliary stent was placed for symptomatic relief. Immunohistochemical staining of the biopsies were negative for CK7 but positive for CK20 and CDX2, in keeping with a colonic primary. There was no clinical evidence of primary CRC but subsequent colonoscopy revealed a colonic mass with histology showing adenocarcinoma. The patient was scheduled for oncology follow up. DISCUSSION: CRC remains one of the leading causes of cancer worldwide and this case highlights an exceptionally unusual way in which this disease presented. Though a rare presentation, clinicians should be aware that it is possible for a cholangiocarcinoma to not be of primary origin. To our knowledge, this is the first known case of painless jaundice from a bile duct tumor as the initial manifestation of a primary colon cancer.Figure 1.: ERCP image showing tumor extruding from CBD.Figure 2.: Standard H&E stain of a) common bile duct tumor and b) colon carcinoma.Figure 3.: Colonoscopy image showing colon carcinoma.