Chocolate-Colored Pseudochylothorax in a Woman with a History of Pleuropulmonary Tuberculosis

Abstract

BACKGROUND Pseudochylothorax is a rare entity, with only a few hundred case reports worldwide. It presents as a pleural effusion rich in lipids, typically with a cloudy, milky appearance. The diagnosis is made based on the levels of cholesterol and triglycerides in the pleural fluid. CASE REPORT This is the case report of a 55-year-old woman with a history of pleuropulmonary tuberculosis that was treated in childhood, with a new infection and treatment in adulthood that evolved to a left pleural effusion. Thirteen years after completing her last treatment for tuberculosis, the patient developed general fatigue and dyspnea on exertion. Computed tomography of the chest confirmed the presence of a pleural collection in the same location as in adolescence, suggesting a chronic evolution with encystation. The patient underwent ultrasound-guided diagnostic thoracentesis. The collected liquid was thick, chocolate-colored, with the following biochemical characteristics: pH, 7.3; glucose, 37.9 mg/dL; LDL, 2059.8 IU/L; total protein, 8.8 mg/dL; triglycerides, 90 mg/dL; adenosine deaminase, 56 U/L; and cholesterol, 300 mg/dL. The effusion was characterized as a pseudochylothorax. The cell count showed 631 000 leukocytes/µL, with 87.9% polymorphonuclear cells. Owing to the patient's respiratory symptoms, an evacuatory thoracentesis was performed. After the procedure, the patient's symptoms improved. CONCLUSIONS Although pseudochylothorax is a rare condition, its possibility must always be kept in mind to avoid the hazards of misdiagnosis. In addition to the 'classic' milky and machine oil appearance, a chocolate-colored appearance should also serve as a clue to the diagnosis of pseudochylothorax.

Figure 1.

Computed tomography images of the chest at the time of presentation. Slices at the upper level – (A) lung window and (B) mediastinal window – showing a small pleural effusion on the left (arrow), with some dense striae extending to the lung parenchyma and some calcified foci (stars), in addition to reduced hemithorax volume; there are still images compatible with bronchiectasis in the posterior region of the right lung (circle). Slices at the middle level – (C) lung window and (D) mediastinal window – show pleural effusion with a dense appearance on the left (arrow), with thickened pleural leaflets and interspersed calcified foci (stars), in addition to reduced hemithorax volume; there are still images compatible with bronchiectasis in the posterior region of the right lung (circle). Slices at the lower level – (E) lung window and (F) mediastinal window – showing dense-looking pleural effusion occupying the left hemithorax (arrow).

Figure 2.

(A) Thick, chocolate-colored pleural fluid. (B) Color detailing with drained pleural fluid.