A Rare Case of Metastatic Merkel Cell Carcinoma to the Stomach and Pancreas Presenting With Upper Gastrointestinal Bleeding and Obstructive Jaundice

Merkel cell carcinoma (MCC) is a rare and aggressive primary neuroendocrine tumor of the skin. Gastrointestinal (GI) metastasis in MCC is uncommon. We present a case of MCC with metastasis to the stomach, duodenum, and pancreas presenting with melena and obstructive jaundice. A large, bleeding metastatic mass was identified in the duodenum. Hemostasis was achieved with coil embolization. Endoscopic retrograde cholangiopancreatography with stenting of the common bile duct was performed to relieve the obstruction. Close surveillance with positron emission tomography/computed tomography scan and possible GI endoscopy should be performed in cases with distant metastasis to identify and treat early GI tract lesions.