Generalized peritonitis arising from small bowel metastasis in a lung cancer patient
A 79-year-old male was admitted to the emergency department with complaints of abdominal pain starting a day prior. Six months earlier, he was diagnosed with lung cancer and liver metastasis (). Chest computed tomography (CT) showed a 2.0 × 1.6 cm sized spiculated mass in the posterior segment of the right upper lobe with an adjacent 1 cm sized metastatic mass. Liver magnetic resonance imaging showed a 1 cm sized nodule in S2 of the liver. The histologic subtype of the lung cancer was poorly differentiated adenocarcinoma. After diagnosis, he refused chemotherapy and only took medicine to control his cough and sputum. According to operation history, he underwent antrectomy with gastrojejunal anastomosis due to gastric ulcer perforation, over 20 years ago. As soon as he arrived at emergency room, we checked the abdominal CT and it showed pneumoperitoneum and aggravation of hepatic metastasis (). Considering disease status and physical status we decided to do an emergency laparotomy. We initially thought the perforation focus was the stomach, but it was a distal ileum located 100 cm proximal from the ileocecal valve. In the abdominal cavity, there was a 1 cm sized free perforation in the ileum, and edematous change of the small bowel with no evidence of peritoneal seeding. We resected about 10 cm length distal ileum and conducted ileoileal end-to-end hand-sewn anastomosis. Postoperative pathological results showed metastatic adenocarcinoma originating from lung cancer. Immunohistochemical (IHC) staining revealed that the tumor cells were positive for cytokeratin 7 (CK7) and thyroid transcription factor (TTF) but negative for CK20 ().\nPostoperatively, the patient was treated in the intensive care unit for pulmonary care with a ventilator, and there was no sign of anastomosis leakage. Five weeks later, he was discharged from the hospital in healthy condition, contrary to our expectations.