Obstructive jaundice secondary to metastatic cancer: A review

Jaundice due to metastatic cancer is much more common than originally appreciated. Studies have shown that up to 21% of malignant biliary obstructions are a result of distant primary malignancies metastatic to the pancreaticobiliary system(1). Jaundice due to biliary stasis occurs from either the diffuse hepatic parenchymal infiltration of malignant cells causing obstruction of the small intrahepatic biliary ducts or by compression of the larger extrahepatic ducts. The latter form of obstruction can be due to intraluminal invasion within the submucosal layer of the bile duct or from external compression secondary to enlarged tumor-infiltrated periportal lymph nodes and masses or pancreatic parenchymal lesions. The clinical differentiation of primary and secondary pancreatico-biliary tumors can be difficult. In fact many of these patients who present with jaundice are initially misdiagnosed with primary cholangiocarcinoma or pancreatic carcinoma. It is important to make this distinction due to the therapeutic implications. Some authors have actually shown improved survival in patients with metastatic disease compared to those with primary pancreatic or bile duct cancers. The most common primary cancers to metastasize to the pancreatico-biliary system are stomach, colon, breast, kidney, and lung (2-5). Other reported primary tumors causing metastatic biliary obstruction include malignant melanoma, lymphoma, gallbladder, ovary, duodenum, esophagus, liver, cervix, uterus, muscle, prostate, bone, and brain. The possibility of metastatic tumor should be considered in all patients with obstructive jaundice, especially if a previous malignant lesion has been identified. Improved imaging (MRI) and biopsy techniques (EUS with FNA) should be helpful in distinguishing primary and metastatic biliary cancer. In this article we will review the characteristics of the common primary tumors causing metastatic biliary obstruction.