Diagnostic and therapeutic approach to endobronchial metastases from extra-thoracic neoplasms: A report of three cases and brief review of literature.

Introduction: Endobronchial metastases (EBMs) are rare, with primary tumours predominantly of breast, renal, and colorectal origin. Bronchoscopy is the diagnostic gold standard, with histological confirmation through immunohistochemical study.
Cases: We presented three cases of EBMs, one secondary to colorectal cancer and two associated with renal tumours. EBM unveiled the extra-thoracic neoplasm in colorectal cancer and was incidentally discovered during renal cancer follow-up. Bronchoscopy revealed an obstructive endobronchial mass in two cases. Histological diagnosis was established via bronchial biopsies (collecting duct renal carcinoma), computed tomography-guided transparietal lung biopsy (clear cell renal carcinoma), and endobronchial mass resection through rigid bronchoscopy (colorectal adenocarcinoma).
Conclusion: In case of an endobronchial lesion, the diagnosis of EBM should be evoked especially when the medical history reports extra-thoracic neoplasms. This diagnostic hypothesis guides the histological diagnosis and leads to an appropriate treatment.