<unk>  remains a rare, possibly under-diagnosed, differential in the case of transudative pleural effusion. There were only 58 reported cases up until January 2006. In the literature, there are under 100 reported cases.
Urinothorax
Hemothorax
Chylothorax
Hydropneumothorax
Hemopneumothorax
Pulmonary hematoma
Fibrothorax
Pneumothorax