A Rare Case of Lymph Node Metastasis Of Hepatoid Adenocarcinoma of the Stomach Presenting as an Abdominal Tumor

A Rare Case of Lymph Node Metastasis Of Hepatoid Adenocarcinoma of the Stomach Presenting as an Abdominal Tumor | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report A Rare Case of Lymph Node Metastasis Of Hepatoid Adenocarcinoma of the Stomach Presenting as an Abdominal Tumor Jiaqi Yao, Jiaqing Jiang, Tao Wang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7551680/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract BACKGROUND Hepatoid adenocarcinoma of the stomach(HAS)is a rare subtype of gastric cancer, which is often misdiagnosed or missed in clinical work due to the lack of case characteristics and other reasons. It is rarer for HAS metastasizes to lymph nodes and manifests as an abdominal tumor. CASE SUMMARY A 58-year-old man came to the hospital for treatment due to elevated AFP. After enhanced CT and MRI, we found a round like tumor near the duodenum. Due to the patient's economic factors, the patient refused PET-CT and gastroscopy. We found and removed this tumor after laparoscopic exploration. The postoperative pathological diagnosis was hepatoid adenocarcinoma; see residual lymphoid tissue and lymphoid follicular structure. To clarify its origin, gastroscopy revealed gastric adenocarcinoma in the gastric horn. Based on pathological diagnosis, we consider HAS lymph node metastasis CONCLUSION We found a rare case of gastric hepatoid adenocarcinoma. Only gastric adenocarcinoma was present in the stomach. The hepatoid adenocarcinoma area metastasized to gastric lymph nodes. And it is very rare to be found clinically in the form of abdominal cavity tumor. This special location and the rarity of gastric hepatoid adenocarcinoma make clinicians prone to misdiagnosis or missed diagnosis. We hope that this report can provide references for the clinical diagnosis and treatment of this kind of rare cancer Hepatoid adenocarcinoma Hepatoid adenocarcinoma of the stomach Lymph node metastasis Abdominal cavity tumor Case report Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Hepatoid adenocarcinoma (HAC) can occur in many parts of the human body, including the gastrointestinal tract, ovaries, uterus, testes, and bladder; however, hepatoid adenocarcinoma of the stomach (HAS) is the most common ( 1 ). This type of gastric cancer accounts for only 1.6–4.3% of gastric cancers, but it often has a strong potential for invasiveness and malignancy ( 2 ). Owing to its special pathological type, patients with HAS usually present with abnormally elevated levels of alpha-fetoprotein (AFP) ( 3 ), which is believed to be mainly derived from the secretion of hepatic cells in tumors ( 4 ). As most patients lack classical early-stage clinical manifestations, they often require endoscopic biopsy and pathological examination before they are diagnosed. Most patients have lymph node or distant metastases at the time of diagnosis; therefore, they usually have a poor prognosis ( 5 , 6 ). Scholars have divided HAS into two major categories: simple and mixed. The difference between the two lies mainly in the presence of a common gastric adenocarcinoma area in addition to the liver-like differentiation area from a histological perspective ( 7 ). Patients with mixed HAS are more likely to be misdiagnosed or missed because the liver-like differentiation area is distinct from the common gastric adenocarcinoma area. We report a rare case of HAC that appeared next to the duodenum, whereas the gastric adenocarcinoma was located in the area of the gastric horn. This suggests that clinicians need to strengthen their knowledge of this type of tumor for future diagnoses. Case Description A 58-year-old male was admitted to our hospital with elevated AFP levels during a physical examination. The patient's height, weight, and body mass index were 170 cm, 69 kg, and 23.88 kg/m 2 . On admission, blood pressure was 122/84 mmHg, pulse rate was 77 beats/min, and respiratory rate was 19 breaths/min. The abdomen was flat, soft, without tenderness or rebound pain. No other abnormalities were observed. We reviewed the patient's AFP level and found that it was significantly further elevated. His tumor indicators were AFP (82.97 ng/ml); CA19-9 (3.01 U/ML), and carcinoembryonic antigen (2.53 ng/ml). We examined the upper abdomen with a magnetic resonance (MR) enhancement of 1.5T and found a round-like mass near the duodenum. The T1 and T2 signals were slightly longer. Diffusion-weighted imaging showed a high signal (Fig. 1 ). We also performed enhanced computed tomography (CT) examination of the upper abdomen and identified a quasi-circular isodense shadow with clear boundaries and a size of about 23 mm × 20 mm on the right side of the descending segment of the duodenum; the enhanced scan showed moderate enhancement and uniform enhancement. No abnormally dense foci were found in the liver, the liver surface was smooth, the liver fissure was not significantly widened, and dilatation was found in the intrahepatic and extrahepatic bile ducts (Fig. 2 ). Unfortunately, the patient refused to undergo positron emission tomography (PET)/CT or painless gastroscopy for economic reasons. To further clarify the nature of this space-occupying lesion, we performed abdominal exploration under laparoscopy after excluding surgical contraindications. We observed a round tumor in the retroperitoneum; the tumor was a single tumor with a regular shape and clear boundaries with the surrounding tissues. Combined with the preoperative examination, we considered that the tumor might be benign but did not rule out the possibility of malignancy. After actively communicating with family members, the patient underwent retroperitoneal tumor resection. The postoperative immunohistochemical results (Fig. 3 ) showed that the histological type of the peritoneal mass was a HAC (residual lymphoid tissue and lymphoid follicular structure). To clarify the source, we performed a gastrointestinal endoscopy with the patient’s consent, which showed that the mucosa of the gastric horn was edematous and erosive, and a 2.5 × 2 cm ulcerative mass with a hard texture was observed. In the antrum and body of the stomach, mucosal congestion, edema, and scattered patchy erosion were observed. No abnormalities were found in the cardia, stomach fundus, or duodenum. A biopsy was performed and the histological results revealed a gastric adenocarcinoma (Fig. 4 ). According to the International Union against Cancer (UICC) Classification of Tumor Lymph Node Metastasis (TNM), 8th edition, the diagnosis was cT3N0M1 cStage IVA. Therefore, this was a case of a rare HAS lymph node metastasis that presented as an abdominal tumor. The clinical diagnosis and treatment process of the patient are shown in Fig. 5 . After the surgery, the patient sought medical treatment from multiple city-based doctors, and all the doctors agreed that the patient was not suitable for other forms of clinical treatment. Discussion HAC is a rare epithelial tumor that can occur in multiple organs of the body, including the stomach, ovaries, and other digestive organs. The origin of HAC remains unclear ( 8 ) due to the uncertainty of the tumor growth site and ease of metastasis. Therefore, clinicians have an insufficient understanding of many rare HACs, including hepatoid differentiated pancreatic ductal carcinoma, neuroendocrine gastric hepatoid adenocarcinoma, hepatoid adenocarcinoma differentiated from enteroblasts, etc. ( 9 – 11 ). Therefore, it is necessary to understand and study the rare sites of HACs. HAS is a rare subtype of gastric cancer, with characteristics of both gastric cancer and HAC. In the present case, the HAS was not a single lesion; it was located in the gastric horn and retroperitoneum. Like most cases of HAS, this patient also showed elevated AFP levels, which is considered a characteristic indicator of HAS ( 12 ). Preoperative AFP levels can also be used to predict patient prognosis, and high AFP is usually an independent risk factor for poor prognosis ( 13 ); however, some patients' blood AFP levels may be negative. As a result, phosphatidylinositol proteoglycan 3 (GPC3) and sal-like protein 4 (SALL4) have become biological indicators of HAS owing to their high positive rates ( 14 ). In addition to these indicators, enhanced CT is an important independent reference factor for differentiating HAS from ordinary gastric cancer ( 15 ). The final diagnosis requires pathological and histological examinations, and surgery remains the preferred treatment ( 6 ). For patients who can tolerate chemotherapy, adjuvant chemotherapy is provided after surgery ( 3 ). Patients with advanced unresectable tumors also seek surgery after chemotherapy ( 2 ). Currently, FOLFOX, cisplatin, and etoposide are selected as chemotherapy regimens for HAS ( 16 , 17 ). Scholars have also found that anti-vascular drugs, such as ramucirumab, have a good curative effect on HAS ( 18 ); however, radiation and immunotherapy require further exploration. Currently, the reported cases of HAS have mostly occurred in the lesser curvature of the stomach, and most of these cases are accompanied by an abnormal elevation in AFP levels. All the patients underwent surgical treatment combined with adjuvant chemotherapy, which achieved therapeutic effects ( 19 – 21 ). This confirms that surgery should be performed as early as possible to treat HAS. Therefore, it is crucial to pay attention to the abnormal elevation of AFP levels in patients and the early detection of tumors through combined examinations, such as gastroscopy. Unlike these reported cases, our case only showed elevated AFP levels and an abdominal mass in the early stages of the disease; however, this type of HAS is rare and most physicians lack knowledge about this rare disease. In the present case, the patient showed only elevated AFP levels at the time of treatment. No tumor was found in digestive system organs through CT, MR imaging, and other examinations. Only one mass was found adjacent to the duodenum. Due to our lack of understanding and knowledge about HAS, the patient refused to undergo PET-CT and painless gastrointestinal endoscopy preoperatively for economic reasons. This led to a certain deviation in our preoperative diagnosis and misled the choice of the subsequent surgical treatment. As a rare subtype of gastric cancer, HAS is often misdiagnosed by physicians during clinical treatment. Currently, in reported cases of HAS, the tumor sites are mostly intragastric tumors. In the present case, HAS was discovered in the form of an abdominal tumor; however, this is rare in clinical practice. We believe that this case report can serve as a reference for physicians in the diagnosis of HAS. Clinicians should identify and diagnose patients with HAS in a timely manner to select more beneficial treatment options. Declarations Conflict of Interest All financial, commercial or other relationships that might be perceived by the academic community as representing a potential conflict of interest must be disclosed. If no such relationship exists, authors will be asked to confirm the following statement: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest . Author Contributions Conception and design: JY,JJ and TW; collection and assembly of data: JY and TW; data analysis and interpretation: all authors; manuscript writing: JY, JJand TW; final approval of manuscript: all authors; accountability for all aspects of the work: all authors. All authors contributed to the article and approved the submitted version. Data availability The data supporting our findings were taken from the patient’s folder, further inquiries can be directed to the corresponding author. Funding No source of funding Ethics declarations Ethics approval and consent to participate This case report was approved by The Medical Ethics Committee of the Second Hospital of Jiaxing and conducted according to the Helsinki and the IACUC guidelines. The above content can be reflected in the patient’s admission authorization letter without the need for an additional ethical code. Written informed consent was obtained from the patient for participation of this clinical case report. Consent for publication Written informed consent was obtained from the patient for the publication of this case report and any accompanying images. Competing interests The authors declare no competing interests. Acknowledgments This is a short text to acknowledge the contributions of specific colleagues, institutions, or agencies that aided the efforts of the authors. References Liu X, Cheng Y, Sheng W, Lu H, Xu X, Xu Y, et al. 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Hepatoid adenocarcinoma of the stomach with pik3ca mutation during pregnancy: A case report with molecular profile. Oxf Med Case Reports (2021) 2021:omab078. 10.1093/omcr/omab078 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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1","display":"","copyAsset":false,"role":"figure","size":151871,"visible":true,"origin":"","legend":"\u003cp\u003eMagnetic resonance imaging of the upper abdomen shows a circular long T1 and T2 signal shadow adjacent to the duodenum.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7551680/v1/847d5ee9a3e424133e3a98e2.png"},{"id":96307189,"identity":"3bd16117-c795-4f52-89bc-c15bb6b431c6","added_by":"auto","created_at":"2025-11-19 15:36:43","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":179660,"visible":true,"origin":"","legend":"\u003cp\u003eComputed tomography of the upper abdomen showed a quasi-circular isodense shadow on the right side of the descending duodenum with clear boundaries, 23 × 20 mm in size, with moderate homogeneous enhancement.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7551680/v1/dbe51705946798278a1617ea.png"},{"id":96307192,"identity":"30a8f28c-1cdf-4a94-b6a4-997581d7bb8b","added_by":"auto","created_at":"2025-11-19 15:36:43","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1153883,"visible":true,"origin":"","legend":"\u003cp\u003eImmunohistochemical findings of abdominal tumors: hepatoid adenocarcinoma, residual lymph node tissues, and lymphoid follicular structure. (A) Hematoxylin and eosin × 40. (B) Tumor cells CK (AE1/AE3) (+) × 40. (C) GPC3 (+) × 40. (D) Ki67 (+, 70%) × 40. (E) SALL4 (+) × 40. (F) Arginase-1 (–) × 40. (G) GATA-3 (–) × 40. (H) Heppar-1 (–) × 40.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7551680/v1/bc9b479eea5cfc1bcff754d0.png"},{"id":96307197,"identity":"8b0b03e7-936a-45b1-8880-b178edd80c4b","added_by":"auto","created_at":"2025-11-19 15:36:43","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1310456,"visible":true,"origin":"","legend":"\u003cp\u003eExamination of the gastric horn revealed a 2.5 × 2.0 cm ulcerative mass in the gastric horn, which was pathologically confirmed as gastric adenocarcinoma.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7551680/v1/041fbc28fe2856994eb1e7cf.png"},{"id":96307193,"identity":"2c27a7f5-47ab-4a8a-9a46-e81807dba65a","added_by":"auto","created_at":"2025-11-19 15:36:43","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":195480,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart of the clinical diagnosis and treatment.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-7551680/v1/0ff6c7ba1f0b1055211cd33a.png"},{"id":100787390,"identity":"321d60de-9099-4f9d-912e-e9d39ee500a0","added_by":"auto","created_at":"2026-01-21 12:01:45","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3923288,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7551680/v1/3c905a98-820d-4ce9-9c15-802ff84edcc4.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A Rare Case of Lymph Node Metastasis Of Hepatoid Adenocarcinoma of the Stomach Presenting as an Abdominal Tumor","fulltext":[{"header":"Introduction","content":"\u003cp\u003eHepatoid adenocarcinoma (HAC) can occur in many parts of the human body, including the gastrointestinal tract, ovaries, uterus, testes, and bladder; however, hepatoid adenocarcinoma of the stomach (HAS) is the most common (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). This type of gastric cancer accounts for only 1.6\u0026ndash;4.3% of gastric cancers, but it often has a strong potential for invasiveness and malignancy (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). Owing to its special pathological type, patients with HAS usually present with abnormally elevated levels of alpha-fetoprotein (AFP) (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e), which is believed to be mainly derived from the secretion of hepatic cells in tumors (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). As most patients lack classical early-stage clinical manifestations, they often require endoscopic biopsy and pathological examination before they are diagnosed. Most patients have lymph node or distant metastases at the time of diagnosis; therefore, they usually have a poor prognosis (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Scholars have divided HAS into two major categories: simple and mixed. The difference between the two lies mainly in the presence of a common gastric adenocarcinoma area in addition to the liver-like differentiation area from a histological perspective (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). Patients with mixed HAS are more likely to be misdiagnosed or missed because the liver-like differentiation area is distinct from the common gastric adenocarcinoma area. We report a rare case of HAC that appeared next to the duodenum, whereas the gastric adenocarcinoma was located in the area of the gastric horn. This suggests that clinicians need to strengthen their knowledge of this type of tumor for future diagnoses.\u003c/p\u003e"},{"header":"Case Description","content":"\u003cp\u003eA 58-year-old male was admitted to our hospital with elevated AFP levels during a physical examination. The patient's height, weight, and body mass index were 170 cm, 69 kg, and 23.88 kg/m\u003csup\u003e2\u003c/sup\u003e. On admission, blood pressure was 122/84 mmHg, pulse rate was 77 beats/min, and respiratory rate was 19 breaths/min. The abdomen was flat, soft, without tenderness or rebound pain. No other abnormalities were observed.\u003c/p\u003e\u003cp\u003eWe reviewed the patient's AFP level and found that it was significantly further elevated. His tumor indicators were AFP (82.97 ng/ml); CA19-9 (3.01 U/ML), and carcinoembryonic antigen (2.53 ng/ml). We examined the upper abdomen with a magnetic resonance (MR) enhancement of 1.5T and found a round-like mass near the duodenum. The T1 and T2 signals were slightly longer. Diffusion-weighted imaging showed a high signal (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). We also performed enhanced computed tomography (CT) examination of the upper abdomen and identified a quasi-circular isodense shadow with clear boundaries and a size of about 23 mm \u0026times; 20 mm on the right side of the descending segment of the duodenum; the enhanced scan showed moderate enhancement and uniform enhancement. No abnormally dense foci were found in the liver, the liver surface was smooth, the liver fissure was not significantly widened, and dilatation was found in the intrahepatic and extrahepatic bile ducts (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Unfortunately, the patient refused to undergo positron emission tomography (PET)/CT or painless gastroscopy for economic reasons.\u003c/p\u003e\u003cp\u003eTo further clarify the nature of this space-occupying lesion, we performed abdominal exploration under laparoscopy after excluding surgical contraindications. We observed a round tumor in the retroperitoneum; the tumor was a single tumor with a regular shape and clear boundaries with the surrounding tissues. Combined with the preoperative examination, we considered that the tumor might be benign but did not rule out the possibility of malignancy. After actively communicating with family members, the patient underwent retroperitoneal tumor resection. The postoperative immunohistochemical results (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) showed that the histological type of the peritoneal mass was a HAC (residual lymphoid tissue and lymphoid follicular structure). To clarify the source, we performed a gastrointestinal endoscopy with the patient\u0026rsquo;s consent, which showed that the mucosa of the gastric horn was edematous and erosive, and a 2.5 \u0026times; 2 cm ulcerative mass with a hard texture was observed. In the antrum and body of the stomach, mucosal congestion, edema, and scattered patchy erosion were observed. No abnormalities were found in the cardia, stomach fundus, or duodenum. A biopsy was performed and the histological results revealed a gastric adenocarcinoma (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). According to the International Union against Cancer (UICC) Classification of Tumor Lymph Node Metastasis (TNM), 8th edition, the diagnosis was cT3N0M1 cStage IVA. Therefore, this was a case of a rare HAS lymph node metastasis that presented as an abdominal tumor. The clinical diagnosis and treatment process of the patient are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. After the surgery, the patient sought medical treatment from multiple city-based doctors, and all the doctors agreed that the patient was not suitable for other forms of clinical treatment.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eHAC is a rare epithelial tumor that can occur in multiple organs of the body, including the stomach, ovaries, and other digestive organs. The origin of HAC remains unclear (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e) due to the uncertainty of the tumor growth site and ease of metastasis. Therefore, clinicians have an insufficient understanding of many rare HACs, including hepatoid differentiated pancreatic ductal carcinoma, neuroendocrine gastric hepatoid adenocarcinoma, hepatoid adenocarcinoma differentiated from enteroblasts, etc. (\u003cspan additionalcitationids=\"CR10\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). Therefore, it is necessary to understand and study the rare sites of HACs. HAS is a rare subtype of gastric cancer, with characteristics of both gastric cancer and HAC. In the present case, the HAS was not a single lesion; it was located in the gastric horn and retroperitoneum. Like most cases of HAS, this patient also showed elevated AFP levels, which is considered a characteristic indicator of HAS (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). Preoperative AFP levels can also be used to predict patient prognosis, and high AFP is usually an independent risk factor for poor prognosis (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e); however, some patients' blood AFP levels may be negative. As a result, phosphatidylinositol proteoglycan 3 (GPC3) and sal-like protein 4 (SALL4) have become biological indicators of HAS owing to their high positive rates (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). In addition to these indicators, enhanced CT is an important independent reference factor for differentiating HAS from ordinary gastric cancer (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). The final diagnosis requires pathological and histological examinations, and surgery remains the preferred treatment (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). For patients who can tolerate chemotherapy, adjuvant chemotherapy is provided after surgery (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). Patients with advanced unresectable tumors also seek surgery after chemotherapy (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). Currently, FOLFOX, cisplatin, and etoposide are selected as chemotherapy regimens for HAS (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). Scholars have also found that anti-vascular drugs, such as ramucirumab, have a good curative effect on HAS (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e); however, radiation and immunotherapy require further exploration. Currently, the reported cases of HAS have mostly occurred in the lesser curvature of the stomach, and most of these cases are accompanied by an abnormal elevation in AFP levels. All the patients underwent surgical treatment combined with adjuvant chemotherapy, which achieved therapeutic effects (\u003cspan additionalcitationids=\"CR20\" citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e). This confirms that surgery should be performed as early as possible to treat HAS. Therefore, it is crucial to pay attention to the abnormal elevation of AFP levels in patients and the early detection of tumors through combined examinations, such as gastroscopy. Unlike these reported cases, our case only showed elevated AFP levels and an abdominal mass in the early stages of the disease; however, this type of HAS is rare and most physicians lack knowledge about this rare disease.\u003c/p\u003e\u003cp\u003eIn the present case, the patient showed only elevated AFP levels at the time of treatment. No tumor was found in digestive system organs through CT, MR imaging, and other examinations. Only one mass was found adjacent to the duodenum. Due to our lack of understanding and knowledge about HAS, the patient refused to undergo PET-CT and painless gastrointestinal endoscopy preoperatively for economic reasons. This led to a certain deviation in our preoperative diagnosis and misled the choice of the subsequent surgical treatment. As a rare subtype of gastric cancer, HAS is often misdiagnosed by physicians during clinical treatment. Currently, in reported cases of HAS, the tumor sites are mostly intragastric tumors. In the present case, HAS was discovered in the form of an abdominal tumor; however, this is rare in clinical practice. We believe that this case report can serve as a reference for physicians in the diagnosis of HAS. Clinicians should identify and diagnose patients with HAS in a timely manner to select more beneficial treatment options.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConflict of Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll financial, commercial or other relationships that might be perceived by the academic community as representing a potential conflict of interest must be disclosed. If no such relationship exists, authors will be asked to confirm the following statement:\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest\u003c/em\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConception and design: JY,JJ and TW; collection and assembly of data: JY and TW; data analysis and interpretation: all authors; manuscript writing: JY, JJand TW; final approval of manuscript: all authors; accountability for all aspects of the work: all authors. All authors contributed to the article and approved the submitted version.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data supporting our findings were taken from the patient’s folder, further inquiries can be directed to the corresponding author.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo source of funding\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics declarations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis case report was approved by The Medical Ethics Committee of the Second Hospital of Jiaxing and conducted according to the Helsinki and the IACUC guidelines. The above content can be reflected in the patient’s admission authorization letter without the need for an additional ethical code.\u0026nbsp;Written informed consent was obtained from the patient for participation of this clinical case report.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWritten informed consent was obtained from the patient for the publication of this case report and any accompanying images.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis is a short text to acknowledge the contributions of specific colleagues, institutions, or agencies that aided the efforts of the authors.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eLiu X, Cheng Y, Sheng W, Lu H, Xu X, Xu Y, et al. 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Oxf Med Case Reports (2021) 2021:omab078. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1093/omcr/omab078\u003c/span\u003e\u003cspan address=\"10.1093/omcr/omab078\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Hepatoid adenocarcinoma, Hepatoid adenocarcinoma of the stomach, Lymph node metastasis, Abdominal cavity tumor, Case report","lastPublishedDoi":"10.21203/rs.3.rs-7551680/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7551680/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBACKGROUND\u003c/h2\u003e\u003cp\u003eHepatoid adenocarcinoma of the stomach(HAS)is a rare subtype of gastric cancer, which is often misdiagnosed or missed in clinical work due to the lack of case characteristics and other reasons. It is rarer for HAS metastasizes to lymph nodes and manifests as an abdominal tumor.\u003c/p\u003e\u003ch2\u003eCASE SUMMARY\u003c/h2\u003e\u003cp\u003eA 58-year-old man came to the hospital for treatment due to elevated AFP. After enhanced CT and MRI, we found a round like tumor near the duodenum. Due to the patient's economic factors, the patient refused PET-CT and gastroscopy. We found and removed this tumor after laparoscopic exploration. The postoperative pathological diagnosis was hepatoid adenocarcinoma; see residual lymphoid tissue and lymphoid follicular structure. To clarify its origin, gastroscopy revealed gastric adenocarcinoma in the gastric horn. Based on pathological diagnosis, we consider HAS lymph node metastasis\u003c/p\u003e\u003ch2\u003eCONCLUSION\u003c/h2\u003e\u003cp\u003eWe found a rare case of gastric hepatoid adenocarcinoma. Only gastric adenocarcinoma was present in the stomach. The hepatoid adenocarcinoma area metastasized to gastric lymph nodes. And it is very rare to be found clinically in the form of abdominal cavity tumor. This special location and the rarity of gastric hepatoid adenocarcinoma make clinicians prone to misdiagnosis or missed diagnosis. We hope that this report can provide references for the clinical diagnosis and treatment of this kind of rare cancer\u003c/p\u003e","manuscriptTitle":"A Rare Case of Lymph Node Metastasis Of Hepatoid Adenocarcinoma of the Stomach Presenting as an Abdominal Tumor","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-11-19 15:36:38","doi":"10.21203/rs.3.rs-7551680/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"981b8ba9-93bf-4f26-a541-be143c2847af","owner":[],"postedDate":"November 19th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-01-21T11:45:36+00:00","versionOfRecord":[],"versionCreatedAt":"2025-11-19 15:36:38","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7551680","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7551680","identity":"rs-7551680","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}