Small Bowel Perforation Due to Rare Metastasis From Stage IV Lung Adenocarcinoma

Lung adenocarcinoma commonly metastasizes to the lymph nodes, bone, nervous system, liver, respiratory system, and adrenal gland. Metastasis to the small bowel is extremely rare and the literature deals mostly with few published case reports. We present a case of a 70-year-old male with a previous history of stage IV lung adenocarcinoma with brain and liver metastases treated with radiotherapy and chemotherapy. He presented to the emergency department with peritonitis and sepsis due to bowel perforation. He underwent an emergency exploratory laparotomy and small bowel resection. Surgical pathology revealed metastatic lung adenocarcinoma as the cause of bowel perforation. He tolerated and recovered from surgery well and was discharged on postoperative day 7. On one-month follow-up as an outpatient, he was doing well and had no complications or complaints from his recent surgery.