Abstract
RATIONALE: Metastatic tumors in the stomach and small bowel are rare. This article reports a case of lung adenocarcinoma metastasizing to the stomach and small bowel. PATIENT CONCERNS: This case study presents the medical history of a 41-year-old male construction worker with a 1-month-long cough and slight chest discomfort. Imaging revealed a tumor in the right middle lobe of the lung, with metastasis to lymph nodes in the mediastinum and right hilar region, as well as a mass in the stomach's greater curvature and multiple lymph node metastases in the abdomen. Thirty-five days after the initial consultation, the patient exhibited worsening symptoms of vomiting and melena. A follow-up computed tomography scan revealed small bowel metastasis, leading to secondary intestinal obstruction and intussusception. DIAGNOSES: Biopsies confirmed poorly differentiated adenocarcinoma in the lung and stomach, with immunohistochemistry supporting a diagnosis of lung adenocarcinoma. Genetic testing showed no mutations or amplification in various genes. INTERVENTIONS: The patient received interventional hemostatic treatment; however, the efficacy of the intervention was poor. OUTCOMES: The patient experienced worsening gastrointestinal symptoms. Despite attempted intervention, the patient ultimately died 78 days after seeking medical attention. LESSONS: The case of lung cancer metastasizing to the stomach and small bowel presented in this article demonstrates high invasiveness and rapid progression. Combined with literature reports, this type of metastasis often indicates a poor prognosis for patients. The long-term benefits of surgical resection remain unclear, and further analysis will be needed with more cases and data in the future.