Cholangiocarcinoma (CCA) is a malignancy arising from the epithelial cells constituting the biliary duct system, either within or outside the hepatic parenchyma [1]. It is divided into intrahepatic, perihilar, and distal forms based on where it arises in the biliary tract [1]. Approximately 90% to 95% of CCAs are histologically classified as adenocarcinomas, which can be further categorized as well, moderately, or poorly differentiated [1]. CCAs most commonly metastasizes to liver, intra-abdominal lymph nodes, and frequently involves the peritoneum, and lungs [2,3]. Metastatic spread to CCA to the stomach is exceedingly rare [4,5]. Perihilar CCA carries a high risk of recurrence after curative intent resection, with one study a rate of 76% at 8 years [6]. Recurrences commonly occur at distant sites, including the retroperitoneal lymph nodes, intrahepatic regions, and peritoneum, as well as at local sites, such as the liver hilum, hepaticojejunostomy, and resection margin [6].

Neoplasms account for 2.9% to 4% of upper gastrointestinal bleeding cases [7]. When the source is a malignant lesion, such as unresectable gastric cancer, endoscopic treatment is usually effective for prompt hemostasis [8]. However, tumor-related bleeding can recur [8]. In the event of rebleeding, transarterial embolization or palliative surgery should be considered for further management.

We report an unusual instance of upper gastrointestinal bleeding resulting from gastric recurrence of a previously resected perihilar CCA. Endoscopic hemostasis was attempted for the malignant bleeding, but it failed to provide long-term control. Persistent anemia ultimately led to surgical resection. Therefore, despite the rarity of gastric recurrence of CCA, it should be considered in patients with a prior history of CCA.

A 75-year-old woman visited the emergency room because of hematemesis that had occurred on the day of her visit. She had a medical history of hypertension, dyslipidemia, and diabetes mellitus. Eight months earlier, she had undergone left lobectomy, caudate lobectomy, and Roux-en-Y hepaticojejunostomy for perihilar CCA. Although distant metastasis was not identified during the preoperative evaluation, lympho-vascular invasion was confirmed in the surgical specimen. As a result, the patient was considered a candidate for chemotherapy. However, chemotherapy was not administered due to recurrent episodes of cholangitis.

Initial laboratory findings showed marked decreased hemoglobin of 4.3 g/dL (normal: 12–15 g/dL). Liver function tests revealed elevated alkaline phosphatase at 441 U/L (normal: 30–120 U/L), gamma-glutamyl transferase at 275 U/L (normal: 0–38 U/L), and total bilirubin of 0.8 mg/dL (normal: 0.2–1.4 mg/dL). Abdominopelvic computed tomography revealed a 38.54 mm thickened lesion in the fundus of stomach (Fig. 1).

Esophagogastroduodenoscopy revealed a 3×3 cm polypoid mass with active bleeding (Fig. 2). Hemostatic powder was applied to the mass, successfully achieving hemostasis (Fig. 3). A biopsy was performed during the endoscopy, and histopathology revealed adenocarcinoma. Given her prior diagnosis of perihilar CCA, the histopathological features observed in the gastric biopsy were more consistent with metastatic CCA rather than primary gastric adenocarcinoma (Fig. 4).

Despite continuous red blood cell transfusions, the patient’s anemia persisted. To control the upper gastrointestinal bleeding and ongoing anemia, a laparoscopic wedge resection of the gastric mass was performed. The resected specimen measured 5.5×4.0×1.0 cm and contained a poorly demarcated, irregular tumor measuring 4.7×3.0×0.9 cm (Fig. 5). Histopathological analysis revealed poorly differentiated tubular adenocarcinoma with lympho-vascular invasion and tumor involvement at the margin of resection. Immunohistochemistry showed cytokeratin (CK)-7 and CK-20, weak positive for CK-19, and overexpression of p53.

Given the absence of abnormalities in the gastric fundus area on a screening endoscopy performed 11 months earlier, the lesion was not considered to be primary gastric cancer. Considering the patient’s earlier endoscopic evaluation and clinical history, the gastric lesion was diagnosed as metastasis from CCA.

Stomach is a rare site for cancer metastasis [9]. Common primary tumors that metastasize to the stomach include those of the esophagus, lung, and breast [9]. Melanoma also has high rate of gastric metastasis [9]. Most gastric metastases including those from esophageal and lung cancer are typically identified within one year of the primary cancer diagnosis [9]. Also, in our patient, gastric metastasis from CCA was detected eight months after surgical resection.

CCA usually metastasizes to intra-abdominal lymph nodes, liver, lung, or peritoneum [2,3]. Gastric metastasis from CCA is an exceptionally uncommon occurrence, particularly with limited cases reported from intrahepatic CCA [4,5]. To our knowledge, only two cases of postoperative gastric metastasis from CCA have been reported to date [10,11]. The first patient, an 80-year-old man with extrahepatic CCA, experienced a gastrojejunostomy recurrence, underwent surgical resection, and remained recurrence-free for 12 months [10]. Another patient, a 63-year-old woman with intrahepatic CCA, was diagnosed with gastric metastasis three years after surgical resection and chose hospice care rather than further treatment [11]. Our case contributes to the scarce literature on postoperative gastric metastasis from CCA.

Normal biliary epithelium consistently expresses CK-7 [12]. Intrahepatic bile duct carcinomas express CK-7 but lack CK-20 expression, whereas extrahepatic bile duct carcinomas co-express both CK-7 and CK-20 [12]. Immunohistochemical staining of our patient’s gastric mass expressed both CK-7 and CK-20, which aligns with the immunophenotype of extrahepatic bile duct carcinoma and supporting the diagnosis of gastric metastasis from CCA. Additional evidence includes the patient’s history of CCA with lympho-vascular invasion. Furthermore, the absence of any fundic polypoid mass on endoscopy performed 11 months prior to the upper gastrointestinal bleeding event further supports that the gastric mass is a metastasis lesion from CCA.

Metastatic gastric lesions are usually asymptomatic [13]. In this context, reports of gastric metastasis presenting with upper gastrointestinal bleeding are limited. A previously published report described a 55-year-old man diagnosed with metastatic lung adenocarcinoma who presented with hematemesis and melena [13]. Gastric metastasis with ulceration was identified and controlled with endoscopic measures and proton pump inhibitor therapy [13]. Another report described a 45-year-old woman previously treated with nephrectomy for renal cell carcinoma and later presented with hematemesis [14]. Endoscopic examination identified a 2 cm ulcerated, raised gastric lesion, subsequently diagnosed as a metastasis lesion originating from renal cell carcinoma [14]. Additionally a case report described a 75-year-old male patient with prior diagnosis of stage IV laryngeal squamous cell carcinoma who presented with hematemesis [15]. Endoscopy examination identified friable mass located in the gastric fundus, which was later confirmed to be a gastric metastasis of the primary cancer [15]. Our case adds to the rare presentations of upper gastrointestinal bleeding caused by gastric metastasis. Early endoscopic hemostasis was performed, allowing further evaluation. In contrast to the previous three cases, our patient required surgical resection due to ongoing anemia despite endoscopic hemostasis. Even though the resection margin was positive, surgery enabled both histopathological diagnosis and control of fatal bleeding.

In conclusion, gastric metastasis from CCA is very uncommon, but it should be considered in patients presenting with hematemesis and a history of CCA. As tumor-related bleeding can recur after endoscopic therapy, surgical intervention may be required to achieve lasting hemostasis.