Utility of Endoscopic Ultrasound in the Work Up for Solitary Hepatobiliary Neuroendocrine Lesions

A 43-year-old woman, with an unremarkable past medical history, presented with a three-week history of generalized itching, jaundice, and abdominal pain. Initial workup showed amorphous, regionally invasive, and obstructing soft tissue mass in the region of the hepatic hilum. The middle third of the main bile duct was subsequently found to harbor a polypoid mass on endoscopic retrograde cholangiopancreatograph. Biopsy revealed nests of neoplastic cells that was subsequently identified as well-differentiated neuroendocrine tumor. A search for a possible primary neuroendocrine tumor was performed and included imaging of the chest, abdomen, and pelvis, a colonoscopy, capsule endoscopy, and an octreotide scan; however, no primary tumor outside of the liver was identified. Surgical debulking was performed, during which intraoperative exploration and ultrasound failed to reveal any extra-hepatic tumor sanctuaries. A few months later, patient underwent endoscopic ultrasound (EUS) for evaluation of recurrent abdominal pain which revealed a small lesion in the pancreas. It was unclear, however, whether it was primary or a metastatic lesion. This case represents a diagnostic challenge and emphasizes the potential utility of EUS in the preoperative work up for any presumable primary hepatobiliary neuroendocrine tumor.