From the Guidelines

Sarcoidosis cannot be caused by exudative pleural effusions.

The provided evidence does not support a direct causal relationship between exudative pleural effusions and sarcoidosis 1.
Sarcoidosis is a systemic granulomatous disease of unknown etiology, characterized by the presence of granulomas in affected organs 1.
The diagnosis of sarcoidosis is based on a combination of clinical, radiographic, and histopathological features, including the presence of granulomas and lymph node involvement 1.
Exudative pleural effusions are not mentioned as a cause or a characteristic feature of sarcoidosis in the provided evidence.
The evidence suggests that sarcoidosis is often associated with lymph node involvement, particularly hilar and mediastinal lymphadenopathy, and that asymptomatic bilateral hilar lymphadenopathy is almost always caused by sarcoidosis 1.

In clinical practice, the presence of exudative pleural effusions should prompt an investigation into possible causes such as infection, malignancy, or autoimmune disorders, but not necessarily sarcoidosis.
A diagnosis of sarcoidosis should be considered in patients with characteristic clinical and radiographic features, such as lymph node involvement and granulomatous inflammation 1.

From the Research

Sarcoidosis is a multisystemic granulomatous disease that can affect multiple organs, including the lungs and pleurae 2, 3, 4, 5, 6.
Pleural effusions are a rare manifestation of sarcoidosis, occurring in approximately 1% of patients with the disease 4.
The pleural fluid in sarcoidosis-associated pleural effusions is typically exudative, lymphocyte-predominant, with high pleural protein levels and normal or mildly elevated lactate dehydrogenase 4.
Exudative pleural effusions can be caused by sarcoidosis, as evidenced by case reports and series 3, 5, 6.
The diagnosis of sarcoidosis-associated pleural effusion involves excluding other etiologies of the pleural effusion and can be made clinically or definitively with pleural biopsy showing noncaseating granulomas 4.

Sarcoidosis-associated pleural effusions are typically exudative and lymphocyte-predominant 3, 4, 5.
The pleural fluid analysis may show a high protein level and normal or mildly elevated lactate dehydrogenase 4.
The diagnosis of sarcoidosis-associated pleural effusion can be confirmed by pleural biopsy showing noncaseating granulomas 4.
Treatment of sarcoidosis-associated pleural effusions typically involves corticosteroids, to which patients typically have an excellent response with resolution of the pleural effusion 4.

Bloody pleural effusion is a rare manifestation of sarcoidosis, occurring in a small percentage of patients with the disease 6.
Sarcoidosis should be included in the differential diagnosis when bloody pleural effusions are detected 6.
Medical thoracoscopy can be helpful in determining the definitive diagnosis of sarcoidosis-associated pleural effusion 6.