Chylothorax

• Fatty lymphatic fluid from the small intestines that leaks into the pleural cavity due to a blockage of the thoracic duct

Etiology

• Congenital: isolated, or associated with lymphangiectasis, lymphangiomatosis, tuberous sclerosis, congenital heart disease, or chromosomal abdnormalities (Trisomy 21 and Turner syndrome)
• Malignancy
  • Lymphoma: probably the most common non-traumatic cause
  • Chronic lymphoid leukemia
  • Lung cancer
  • Mediastinal cancer
  • Multiple myeloma
  • Lymphangioleiomyomatosis (LAM)
  • Metastatic carcinoma
• Infection
  • Tuberculous lymphadenitis
  • Aortitis
  • Histoplasmosis
  • Filariasis
• Rare causes
  • Castleman disease
  • Benign mediatinal tumour
  • Sarcoidosis
  • Kaposi sarcoma
  • Yellow nail syndrome
  • Noonan syndrome
  • Down syndrome
  • Waldenström macroglobulinemia
  • Amyloidosis
  • Venous thrombosis
  • Thoracic radiation
  • Goiter
• Trauma: surgical or nonsurgical

Differential Diagnosis

• Milky fluid
  • Cholesterol effusion: has cholesterol ≥5.18 mmol/L in the pleural fluid
  • Empyema: signs of infection
  • Tube feed leak or parenteral nutrition leak: high triglycerids in the fluid, and imaging showing misplaced catheter or tube
• Non-milky effusion
  • Any exudative effusion