Causes of chylothorax and pseudochylothorax
Chylothorax:

  • Trauma:

thoracic surgery (especially if involving posterior mediastinum, for example, oesophagectomy), thoracic injuries

  • Neoplasm:

lymphoma or metastatic carcinoma

  • Miscellaneous:

disorders of lymphatics (including lymphangioleiomyomatosis), tuberculosis, cirrhosis, obstruction of the central veins, chyloascites

  • Idiopathic (about 10%)

Pseudochylothorax:

  • Tuberculosis

  • Rheumatoid arthritis