Chylothorax due to enlarged tuberculous lymph nodes

Description

A 37-year-old man was evaluated for a 2-month history of fever, cough and weight loss. He was diagnosed with AIDS 3 years ago, had a recent CD4 cells count of 199 /μL and was receiving antiretroviral therapy. Physical examination revealed decreased breath sounds and dullness to percussion on the left base. Chest radiograph showed a moderate sized left pleural effusion. Thoracentesis yielded a milky fluid with a leucocyte count of 792 cells/μL (94% lymphocytes), total protein 5.4 g/dL (serum 6.4 g/dL), lactate dehydrogenase 347 IU/L (serum 875  IU/L), glucose 112  mg/dL, adenosine deaminase 48 IU/L, cholesterol 72 mg/dL (serum 102 mg/dL) and triglycerides 281 mg/dL (serum 83 mg/dL). Results of pleural fluid and sputum smears and cultures for mycobacteria were negative. CT revealed a left pleural effusion and a diffuse miliary pattern (figure 1A). A retrocrural enlarged lymph node compressing the cisterna chyli along with a dilated thoracic duct was also noted (figure 2). These radiological signs cleared after 6 months of antituberculous therapy (figure 1B).

Learning points.

• Tuberculous chylothorax is a rare condition, with only anecdotal cases being reported in literature.¹

• Occasionally, thoracic duct obstruction leading to the leakage of chyle into the pleural space may result from tuberculous mediastinal lymph nodes.²

• Anti-tuberculous therapy along with therapeutic thoracenteses usually solve the chylothorax.

Figure 1.

CT showing a left pleural effusion and numerous small lung nodules diffusely distributed (A), with resolution after 6 months of antituberculous treatment (B).

Figure 2.

CT demonstrating an enlarged retrocrural lymph node which compresses the cisterna chyli (arterisk), along with a dilated thoracic duct (arrowheads).