S5896 A Diagnostic Challenge: Metastatic Melanoma Presenting as Acute Liver Injury With Gastrointestinal Involvement

Introduction: The fifth most common cancer in the United States, malignant melanoma, can frequently metastasize to the liver and the gastrointestinal (GI) tract. We present a case of a woman with a history of cutaneous melanoma who developed severe right upper quadrant abdominal pain and anorexia in association with an acute liver injury in the setting of biopsy proven metastatic melanoma. Case Description/Methods: A 55-year-old woman with diabetes, obesity, metabolic dysfunction-associated steatotic liver disease, cutaneous melanoma (stage 1B) status post wide local excision with negative sentinel lymph node biopsies in 9/2024 presented in late 4/2025 with 10 days of worsening right upper quadrant pain, anorexia, and loose stools. Six months prior, a PET scan showed non-specific uptake without definitive evidence of recurrence. An ultrasound in 4/2025 showed innumerable hypodense hepatic lesions. A subsequent magnetic resonance imaging (MRI) revealed regenerative nodules. On presentation, she was tachycardic with abdominal tenderness and guarding. Laboratory studies showed a predominantly cholestatic liver injury. Lactate dehydrogenase (LDH) was elevated (4993 U/L). Alpha-fetoprotein and iron levels were normal. Infectious and autoimmune evaluation were unremarkable. Computed tomography angiogram was negative for mesenteric ischemia and notable for hepatosplenomegaly with hypodense splenic lesions. Endoscopic (EGD) evaluation demonstrated an ulcerated melanotic nodule along the greater curvature of the gastric body and hyperpigmented spots in the duodenum. Biopsies showed foci of malignant melanoma. A percutaneous liver biopsy revealed metastatic malignant melanoma arising in a background of steatohepatitis. The patient declined further staging or treatment and transitioned to hospice, expiring 2 days later. Discussion: Melanoma may metastasize to any organ including the liver and less commonly the GI tract, favoring the small intestine followed by the stomach and colon. Diagnosis of GI tract metastases may be challenging or delayed until autopsy given its nonspecific symptoms and ability to occur at any time. Distinguishing metastatic melanoma as a cause for ALI from other more common causes such as drug induced liver injury and viral hepatitis can be challenging, though LDH has been used as a marker of tumor involvement and a predictor of liver failure. In this case, frequent imaging and lab work in the months prior to presentation did not demonstrate evidence of recurrent or metastatic disease highlighting the complexity in establishing this diagnosis.