Duodenal Lung Metastasis Presenting with Upper Gastrointestinal Bleeding: a case report

Introduction: Small bowel metastases from lung adenocarcinoma are rare and usually occur in advanced-stage disease. Duodenal involvement is particularly uncommon and may present with gastrointestinal bleeding. Case Presentation: A 52-year-old heavy smoker presented with cough and superior vena cava syndrome. Imaging revealed an 11 cm mass in the upper lobe of the right lung with mediastinal invasion, and bronchoscopic cytology confirmed lung adenocarcinoma without targetable mutations. Despite palliative radiotherapy and platinum-based chemotherapy, the disease rapidly progressed with multiple systemic metastases. Four months after diagnosis, the patient was admitted with melena, asthenia and severe anaemia (Hb 5.8 g/dL). Initial upper gastrointestinal endoscopy showed no lesions up to the second portion of the duodenum. However, further advancement of the gastroscope identified multiple ulcerated “volcano-like” lesions in the third and fourth portions of the duodenum. Histopathological and immunohistochemical evaluation confirmed metastatic lung adenocarcinoma. Given the extensive disease burden and poor prognosis, best supportive care was instituted, and the patient died seven days later. Conclusion: Duodenal metastases from lung adenocarcinoma are exceptionally rare and may manifest as upper gastrointestinal bleeding. This case emphasizes the importance of thorough distal duodenal evaluation during upper endoscopy in patients with melena or anaemia, particularly when no bleeding source is identified in the proximal duodenum.