Small Bowel Intussusception due to Multiple Intestinal Metastases from Lung Adenocarcinoma

Metastatic small bowel tumors are rare. They often present with small bowel occlusion, bleeding, perforation, or intestinal intussusception. Pulmonary adenocarcinoma with metastasis to the small intestine causing intussusception is exceedingly rare. A 72-year-old male patient with a past medical history of left lung adenocarcinoma, presented to the emergency department with abdominal pain and vomiting. On admission, an X-ray of the abdomen without preparation showed some hydroaeric levels on the small intestine. The abdominopelvic computed tomography (CT) scan revealed an ileo-ileal invagination, with an image of the invagination rod. The patient underwent a surgical resection of the small bowel with the removal of the ischemic areas and immediate anastomosis. Macroscopic examination of the surgical specimen revealed five tumor masses varying in size between 1 and 4 cm. The histological examination of the samples taken from these tumors, coupled with an immunohistochemical study confirmed the diagnosis of intestinal metastases of pulmonary origin expressing cytokeratin 7 (CK7) and thyroid transcription factor 1 (TTF1) but negative for CK20, chromogranin, and synaptophysin. The postoperative course was uneventful, and the symptoms transiently recovered. However, the patient died 3 months later. We should consider multiple metastatic lesions in adult intussusception, especially in patients with a past medical history of lung cancer