Endobronchial Metastasis from Rectal Adenocarcinoma without Liver Involvement: A Case Report

Abstract

The lungs are common sites for secondary metastases. However, endobronchial metastases from extrapulmonary primary sites are rare, and their definition and developmental modes have not yet been fully elucidated. The liver is the most common site of hematogenous spread from colon tumors, which then progresses to pulmonary sites. Herein, we report a case of adenocarcinoma of the rectum, status post-radical proctectomy and postoperative chemotherapy. After a 2-year disease-free interval, the patient was brought to the emergency department and hospitalized with pulmonary symptoms similar to pneumonia. Computed tomography disclosed lobar consolidation of the right upper lobe and obstruction of the right main bronchus. Metastatic lung cancer was confirmed with histopathology of a biopsy specimen obtained through bronchoscopy. Hematogenous dissemination was most likely because of the additional pulmonary nodule at the right lower lobe. Due to the tumor being unresectable, the patient received radiation therapy for palliative treatment. We also reviewed the literature on endobronchial colorectal metastasis. The median time of metastasis to the lung from the primary site at the colon is about 4 years, and treatment is variable on account of the individual condition.