Malignant biliary obstruction generally results from primary malignancies of the pancreatic head, bile duct, gallbladder, liver, and ampulla of Vater. Metastatic lesions from other primaries to these organs or nearby lymph nodes are rarer causes of biliary obstruction. The most common primaries include renal cancer, lung cancer, gastric cancer, colorectal cancer, breast cancer, lymphoma, and melanoma. They may be difficult to differentiate from primary hepato-pancreato-biliary cancer based on imaging studies, or even on biopsy. There is also no consensus on the optimal method of treatment, including the feasibility and effectiveness of endoscopic intervention or surgery. A thorough review of the literature on pancreato-biliary metastases and malignant biliary obstruction due to metastatic non-hepato-pancreato-biliary cancer is presented. The diagnostic modality and clinical characteristics may differ significantly depending on the type of primary cancer. Different primaries also cause malignant biliary obstruction in different ways, including direct invasion, pancreatic or biliary metastasis, hilar lymph node metastasis, liver metastasis, and peritoneal carcinomatosis. Metastasectomy may hold promise for some types of pancreato-biliary metastases. This review aims to elucidate the current knowledge in this area, which has received sparse attention in the past. The aging population, advances in diagnostic imaging, and improved treatment options may lead to an increase in these rare occurrences going forward.

• Bile duct obstruction
• Obstructive jaundice
• Pancreas
• Metastasis
• Endoscopic retrograde cholangiopancreatography

• Aged
• Ampulla of Vater/pathology
• Bile Ducts
• Biliary Tract Neoplasms/pathology
• Cholangiopancreatography, Endoscopic Retrograde/adverse effects
• Cholestasis/surgery
• Gallbladder
• Humans

Secondary pancreatic tumors are uncommon, with the majority originating from primary gastrointestinal or lung cancers. We present the case of a 42-year-old woman with squamous cell carcinoma of the pancreas, found to be human papillomavirus–positive on in situ hybridization. After extensive work-up, the patient was determined to have a previously undiagnosed, asymptomatic head and neck primary malignancy. There is sparse literature discussing metastatic human papillomavirus–positive squamous cell carcinoma to the pancreas. This report highlights the importance of including this diagnosis when considering a differential for secondary pancreatic tumors, especially squamous etiology.

• Endoscopic ultrasound-guided fine-needle aspiration
• Pancreas
• Pseudocyst
• Squamous cell carcinoma

• Acute Disease
• Carcinoma, Squamous Cell/diagnosis
• Cysts
• Endoscopic Ultrasound-Guided Fine Needle Aspiration
• Humans
• Male
• Middle Aged
• Pancreas/diagnostic imaging
• Pancreatic Neoplasms/diagnosis
• Pancreatitis