S5699 Hidden in Plain Sight: A Polycystic Liver Concealing Metastatic Pancreatic Cancer

Introduction: Polycystic kidney disease (PKD) often involves other organ systems including the liver. While most cases have little impact on the liver's synthetic function, this condition can significantly alter the hepatic architecture thus obscuring other conditions. We present a case of metastatic pancreatic cancer with liver metastasis which was initially concealed behind a background of benign cysts. Case Description/Methods: A 66-year-old man with a kidney transplant 3 years prior due to PKD and diabetes presents to the emergency department with recurrent fevers. He was recently hospitalized for klebsiella bacteremia of unknown origin and discharged on appropriate antibiotics but represented several days later with persistent fevers and abdominal pain. His labs were notable for a white blood cell 12.1 K, alkaline phosphatase 198 g/dL, and CRP 123 mg/L. Computed tomography (CT) abdomen and pelvis showed extensive polycystic disease involving the liver and pancreas. An infectious workup including bacterial, fungal and viral cultures, serologies and cerebrospinal fluid analyses were all negative. PET CT imaging showed multiple foci of increased FDG activity throughout the liver and pancreatic body. Subsequent MRI identified innumerable non-cystic hepatic lesions and an ill-defined pancreatic body mass. Endoscopic ultrasound showed an ill-defined hypoechoic mass in the pancreatic neck with upstream pancreatic ductal dilation and a solid mass in the liver, both of which were biopsied. Pathology returned positive for adenocarcinoma. Discussion: This case highlights the challenges in diagnosing underlying malignancies in patients with complex anatomic abnormalities, such as those with PKD, and the importance of inter-specialty collaboration along with utilization of advanced endoscopic techniques to confirm diagnosis.