S3392 Beyond the Skin: Melanoma’s Hidden Path to the Biliary Tree

Introduction: Melanoma is known to metastasize to almost any organ system; most commonly to the lungs, liver, and brain. We present a patient with a prior diagnosis of pT2a pN0 cM0 melanoma status post resection with positive margins who presented with progressive right upper quadrant (right upper quadrant) pain, found to have a malignant biliary obstruction. Case Description/Methods: A 50-year-old man with a history of cutaneous melanoma status post resection 3 years prior presented with right upper quadrant abdominal pain, nausea, vomiting, and weight loss. A right upper quadrant ultrasound was significant for cholelithiasis but was otherwise unremarkable. As his symptoms continued, there was concern for biliary cholic, and he underwent a cholecystectomy. Shortly after, the patient developed jaundice and severe pruritus. Laboratory workup was remarkable for total bilirubin 9.1 mg/dL. Computed Tomography scan demonstrated a heterogeneous 5.6 × 4.8 cm mass within the liver hilum, which caused upstream dilation of the proximal common bile duct and intrahepatic bile ducts as well as paraaortic and interaortocaval lymphadenopathy. He underwent endoscopic ultrasound with fine needle biopsy (FNB) of a lymph node and endoscopic retrograde cholangiopancreatography (ERCP), which showed a 15 mm common hepatic duct stricture with upstream dilation concerning for malignancy. Wire-guided balloon dilation to 4 mm and placement of a 10 Fr × 12 cm transpapillary plastic biliary stent was pursued with subsequent spontaneous biliary drainage. Pathology from the prior cholecystectomy and FNB was consistent with metastatic melanoma. He was discharged with a medical oncology referral. Discussion: In 1 post-mortem review, very few patients with metastatic melanoma had gallbladder and biliary tree involvement, 15% and 6%, respectively. Symptomatic metastatic melanoma to the biliary tree is even more rare, and therefore, there are limited recommendations regarding management. Biliary stenting has been shown to have some palliation benefits. In cases without concurrent metastasis, it is reasonable to consider surgical resection. Despite treatment options, metastatic melanoma to visceral sites has a median survival time of 4-9 months. The utility of chemotherapy and immunotherapy is understudied in this rare presentation of melanoma. However, the most recent data on metastatic melanoma has shown promising response rates with immune checkpoint inhibitors and targeted therapy. While rare, metastatic melanoma masquerading as obstructive jaundice is an important differential to consider in the right clinical context.