Capsule Endoscopy-Based Diagnosis of Lung Squamous Cell Carcinoma Associated with Abdominal Pain and Metastasis to Small Intestine: A Case Report

Gastrointestinal metastases of lung cancer are relatively uncommon, yet occur at a higher frequency than would be expected among patients that exhibit a longer survival interval. Metastases that arise in the small intestines are often associated with no or few symptoms such that their early diagnosis can be challenging. In this report, we describe an extremely rare case of a lung squamous cell carcinoma that had metastasized to the small intestine and was associated with symptoms of abdominal pain. The patient underwent capsule endoscopy which detected an irregular mass in the distal ileum that was hemorrhagic, after which laparoscopic ileal resection and anastomosis in parallel with partial bladder resection were performed. Subsequent pathological biopsy confirmed that the intestinal mass was consistent with metastatic squamous cell carcinoma. With surgery and subsequent maintenance therapy with targeted drugs, the survival of the patient was more than 6 months. As a noninvasive testing strategy, capsule endoscopy can be easily performed to support etiological diagnostic efforts in cases where other diagnostic options are lacking. Early diagnosis and therapeutic intervention can contribute to better prognostic outcomes for GMLC patients.