Extensive endobronchial growth of metastatic hepatocellular carcinoma resulting in respiratory failure: A case report

Intrabronchial involvement by metastatic tumors from extrapulmonary primary sites is referred to as "endobronchial metastasis", which is an uncommon mode of metastasis. Although various primary sites (for example, breast, colon, and kidney) have been reported previously, endobronchial metastasis of hepatocellular carcinoma (HCC) is rare. Here, we report a case of a 71-year-old woman with hepatitis C-related HCC, in whom respiratory failure due to bilateral endobronchial metastasis occurred. Notably, long tree-like tumor shadows reminiscent of the structure of the bronchial tree were observed in the bilateral lungs on computed tomography scan, and postmortem analysis clearly revealed metastatic HCC growing and spreading extensively in the lumina of the bronchi. This growth pattern is in sharp contrast to the ordinary endobronchial metastasis, which involves a relatively short segment of the unilateral bronchus. This is the first case report of bilateral and extensive spreading of endobronchial metastatic HCC, and this phenomenon should be considered as a cause of dyspnea in advanced HCC patients.