B0620 - Hepatoid Gastric Adenocarcinoma

Rana Mohamed, MD¹, Lawson Cate, MD¹, Saeed Graham, MD^2
1East Carolina, Greenville, NC; ²East Carolina University Brody School of Medicine, Greenville, NC

Introduction: Hepatoid gastric adenocarcinoma is a rare extrahepatic tumor, characterized by morphological similarity to hepatocellular carcinoma and production of alpha-fetoprotein. We report a case of gastric hepatoid adenocarcinoma occurring at the esophagogastric junction; a location scantily reported of this lesion subtype.

Case Description/Methods: Our patient presented with abdominal pain, regurgitation, weight loss, and bulky retroperitoneal lymphadenopathy on imaging. Later, two enlarging abdominal wall masses emerged prompting biopsy, staining positive for glypican-3, Hep-Par-1, and alpha-fetoprotein. On endoscopy, an ulcerating mass was noted at the esophagogastric junction extending into the cardia. Next-generation sequencing identified 68th percentile PD-L1 expression. Treatment was initiated with oxaliplatin, 5-fluorouracil, leucovorin, and nivolumab. After initial regression, he later succumbed.

Discussion: Hepatoid adenocarcinoma accounts for only 0.17-15% of gastric cancer subtypes[1]. Most reports involve lesions occurring solely in the stomach — very few describe occurrences involving the esophagogastric junction supplementing the uniqueness of this case. It also commonly co-occurs with metastatic liver lesions[2] which were not so in this circumstance. These tumors produce alpha-fetoprotein and may also stain positive for novel hepatocellular tumor markers: glypican-3 and Hep-Par-1. In the phase 3 Checkmate 649 trial, the PD-1 inhibitor nivolumab combined with chemotherapy was superior to chemotherapy alone[3]. There are currently no evidence-based recommendations for therapy. Current treatment strategies are extrapolated from other gastric cancers lending to a dismal prognosis.


Disclosures:


Rana Mohamed, MD¹, Lawson Cate, MD¹, Saeed Graham, MD². B0620 - Hepatoid Gastric Adenocarcinoma, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.