Sun SY, Elliott T, Johnstone M, Facey M, Chin JK, Gangadharan SK. Marked elevation of alpha fetoprotein caused by hepatoid adenocarcinoma of stomach: A case report. World J Gastrointest Oncol 2026; 18(10): 123542 [DOI: 10.4251/wjgo.123542]
Corresponding Author of This Article
Shi-Yao Sun, MD, Department of Gastroenterology, Grampians Health, 1 Drummond St N, Ballarat 3350, Victoria, Australia. sharon.shiyao.sun@gmail.com
Research Domain of This Article
Gastroenterology & Hepatology
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case-report
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Sun SY, Elliott T, Johnstone M, Facey M, Chin JK, Gangadharan SK. Marked elevation of alpha fetoprotein caused by hepatoid adenocarcinoma of stomach: A case report. World J Gastrointest Oncol 2026; 18(10): 123542 [DOI: 10.4251/wjgo.123542]
World J Gastrointest Oncol. Oct 15, 2026; 18(10): 123542 Published online Oct 15, 2026. doi: 10.4251/wjgo.123542
Marked elevation of alpha fetoprotein caused by hepatoid adenocarcinoma of stomach: A case report
Shi-Yao Sun, Timothy Elliott, Maddison Johnstone, Matthew Facey, Jong-Khen Chin, Sajith K Gangadharan
Shi-Yao Sun, Timothy Elliott, Jong-Khen Chin, Sajith K Gangadharan, Department of Gastroenterology, Grampians Health, Ballarat 3350, Victoria, Australia
Maddison Johnstone, Matthew Facey, Department of Pathology, Grampians Health, Ballarat 3350, Victoria, Australia
Co-corresponding authors: Shi-Yao Sun and Sajith K Gangadharan.
Author contributions: Sun SY, Elliott T, Chin JK, and Gangadharan SK contributed to manuscript conception, writing and revision of the manuscript; Johnstone M and Facey M performed and interpreted the pathological examinations; and all authors have read and approved the final manuscript.
AI contribution statement: AI tools were used solely for linguistic refinement. No AI tool was involved in the generation of research data, interpretation of results, or formulation of conclusions. The authors carefully reviewed and verified all AI-assisted outputs and take full responsibility for the scientific content of the manuscript.
Informed consent statement: Informed written consent was obtained from the deceased patient’s next of kin for publication of this report and any accompanying images.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Corresponding author: Shi-Yao Sun, MD, Department of Gastroenterology, Grampians Health, 1 Drummond St N, Ballarat 3350, Victoria, Australia. sharon.shiyao.sun@gmail.com
Received: May 25, 2026 Revised: July 3, 2026 Accepted: August 5, 2026 Published online: October 15, 2026 Processing time: 119 Days and 14.1 Hours
Abstract
BACKGROUND
Alpha-fetoprotein (AFP) is primarily used as a tumour marker for hepatocellular carcinoma and germ cell tumours. Hepatoid adenocarcinoma of stomach (HAS) is a rare and aggressive subtype of gastric cancer with hepatocyte differentiation. We report a case of extremely high AFP levels caused by HAS.
CASE SUMMARY
A 75-year-old man was admitted with abdominal pain and weight loss. Tumour markers showed an unusually high AFP of 889200 ng/mL. Computed tomography showed an exophytic mass in the stomach with extensive portal vein thrombosis. Gastroscopy showed a 5 cm ulcerated mass on the lesser curve of the stomach. Histology confirmed hepatoid adenocarcinoma, which mimics hepatocellular carcinoma. The immunohistochemistry was positive for cytokeratin AE1AE3, caudal type homeobox 2, hepatocyte paraffin 1 and AFP. He was treated with fluorouracil leucovorin oxaliplatin and nivolumab. However, he died due to progressive disease.
CONCLUSION
Markedly high AFP levels should prompt physicians to evaluate for uncommon causes including HAS.
Core Tip: We report a rare case of hepatoid adenocarcinoma (HAC). Markedly elevated alpha-fetoprotein levels should prompt physicians to evaluate for uncommon causes including HAC of stomach. Histology and immunohistochemistry are integral to establishing the diagnosis. Gastroscopy is also a crucial diagnostic step. There is currently no established treatment protocol for HAC of stomach; however, treatment for metastatic gastric cancer has been used. A low serum alpha-fetoprotein level is generally associated with better survival, but long-term studies are required to confirm this.
