Malignant transient pleural transudate: a sign of early lymphatic tumoral obstruction.

In the absence of a responsible comorbid condition, the transudative character of a pleural effusion in patients with malignancy does not imply a favorable outcome. We report a case of colon carcinoma metastatic to lung and pleura presenting as a bilateral transudative pleural effusion. Tumoral diffuse lymphatic permeation was identified as the cause of lymphatic obstruction on pleural and transbronchial biopsies. The transudative character of the pleural effusion was transient denoting its obstructive origin.