Metastatic prostate cancer initially presenting as chylothorax: A case report

Chylothorax is caused by disruption or obstruction of the thoracic duct, which results in leakage of chyle in the pleural space. The most common etiologies are malignancy and trauma. Among the causative malignancies, lymphoma is the most common, followed by primary lung cancer, mediastinal tumors, and other metastatic malignancies. Conversely, prostate cancer has rarely been reported as the cause of chylothorax. We herein report a case of metastatic prostate cancer initially presenting as chylothorax, with disappearance of the pleural effusion after the initiation of androgen deprivation therapy. Moreover, we also discuss the various rare manifestations of metastatic prostate cancer, including chylothorax.