Beyond the Bowel: Lung Cancer Presenting as Complicated Diverticulitis.

Lung cancer is often diagnosed at advanced stages frequently metastasizing to organs like the liver, adrenal glands, brain and bones. However, gastrointestinal metastasis, especially to the small intestine, is rare. We report a patient who presented with a perforated small bowel, requiring emergent laparotomy. Imaging suggested an infectious process, but subsequent workup revealed jejunal perforation and poorly differentiated lung cancer. Despite being a candidate for immunotherapy alone, the patient opted for hospice. This case emphasizes the atypical presentation of lung cancer as a gastrointestinal complication and underscores the importance of keeping malignancy in the differential for a perforated small bowel.