Metastatic large cell carcinoma of the lung: A rare cause of acute small bowel obstruction.

Here, we report a case of acute intestinal obstruction as the initial presentation of primary lung cancer in a male patient. Abdominal computed tomography (CT) showed multiple polypoid masses and regional lymphadenopathy with small bowel obstruction. The patient underwent emergency surgery for multiple luminal malignancy with mesenteric masses. According to the various clinicopathological features, the tumor was confirmed to be metastatic large cell carcinoma originating from the lung. Large masses in the left lower lobe of the lung were identified on the chest CT after emergency surgery, and non-small cell lung cancer (NSCLC), not otherwise specified (NOS), was finally diagnosed on biopsy through bronchoscopy.