대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Pseudochylous Pleural Effusion in Chronic Tuberculous Empyema

Radiologic Findings

Chest radiograph shows well-defined homogenous increased opacification in the left lower hemithorax, with a mediastinal shift to the contralateral hemithorax.

Contrast뻛nhanced CT scans show diffuse pleural thickening with curvilinear and nodular calcifications in the wall of the empyemic cavity. Note multiple fat component lesions within the empyemic cavity. The CT number of the low-attenuating area is -90HU.

Brief Review

A chyliform pleural effusion, or pseudochyle, which was so named because it is not related to the disruption of the thoracic duct, is turbid or milky because of a high lipid content. In other words, all high-lipid nonchylous effusions can be called chyliform or pseudochylous pleural effusions.

The precise pathogenesis of chyliform pleural effusions is unknown. The origin of the lipids in these effusions is thought to be degenerating red and white blood cells in the pleural fluid. The process is apparently initiated by pleurisy with thickened and sometimes calcified pleura. The diseased pleura may result in an abnormally slow transfer of cholesterol and other lipids out of the pleural space and lead to the accumulation of cholesterol in the pleural fluid. Tuberculosis is the most common disease associated with the onset of chronic pleurisy that eventually leads to chyliform effusion. Other reported underlying diseases include rheumatoid lung disease, alcoholism, syphilis, diabetes, Meigs syndrome, malignancy, paragonimiasis, and trauma or hemothorax.

The mean duration of pleural effusion before it turns chyliform is 5 years, but a few chyliform effusions have been known to develop within a year of onset.

Pseudochylous pleural effusion shows unique CT features of a presence of a fat-fluid or fat-calcium level in loculated pleural effusion with diffuse pleural thickening.

References

1. Jae-Woo Song, MD, Jung-Gi Im, MD, Jin Mo Goo, MD, Hyae Young Kim, MD, Chi Sung Song, MD and Jeong Sang Lee, MD. Pseudochylous Pleural Effusion with Fat-Fluid Levels: Report of Six Cases Radiology. 2000;216:478-480.

Keywords

Pleura, Non-infectious inflammation,