What type of pleural effusion is associated with pulmonary embolism (PE) and neoplastic disease?

From the Guidelines

Pleural effusions associated with pulmonary embolism (PE) and neoplastic disease are typically exudative, with the majority of those caused by PE being exudates (80%) and nearly all neoplastic effusions being exudative due to local inflammation, increased vascular permeability, or lymphatic obstruction caused by the tumor. This is supported by studies such as 1, which notes that nearly all neoplasms have been reported to involve the pleura, with lung carcinoma being the most common, and that cancer-related pleural effusions are typically exudative. Additionally, 1 states that 80% of pleural effusions associated with pulmonary embolism are exudates, while 20% are transudates.

Some key points to consider when evaluating pleural effusions in the context of PE and neoplastic disease include:

• The presence of a high red blood cell count in the pleural fluid, which may suggest malignancy, pulmonary infarction, or trauma, as noted in 1.
• The clinical context, as the diagnosis of PE should be pursued on clinical grounds with a high index of suspicion, according to 1.
• The fact that neoplastic effusions can be caused by a variety of mechanisms, including direct tumor invasion, hematogenous spread, and lymphatic involvement, as discussed in 1.
• The importance of distinguishing between malignant and paramalignant effusions, as treatment approaches may differ, as noted in 1 and 1.

In terms of management, the focus should be on relieving symptoms and improving quality of life, particularly in patients with malignant pleural effusions, who have a poor prognosis with a median survival of 3-12 months. This is supported by studies such as 1 and 1, which emphasize the importance of patient-centered outcomes and minimally invasive interventions. Overall, a thorough understanding of the underlying causes and mechanisms of pleural effusions in the context of PE and neoplastic disease is crucial for proper diagnosis and management.

From the Research

Type of Pleural Effusion Associated with Pulmonary Embolism (PE) and Neoplastic Disease

• The type of pleural effusion associated with pulmonary embolism (PE) is usually an exudate, occasionally transudative 2, 3, 4, 5.
• Pleural effusions due to pulmonary embolism are typically small, occupying less than one-third of the hemithorax in 90% of cases 3.
• The most common causes of pleural effusion are congestive heart failure, cancer, pneumonia, and pulmonary embolism 6.
• Neoplastic disease, particularly lung cancer, is a common cause of malignant pleural effusion 6.
• The presence of pleuritic chest pain in a patient with a pleural effusion is highly suggestive of pulmonary embolism 2, 4.

Characteristics of Pleural Effusions in Pulmonary Embolism

• Pleural effusions secondary to pulmonary embolism can be found in around one-third of all cases with pulmonary embolism 5.
• They are small, mostly unilateral, often but not always hemorrhagic 5.
• They are always exudates with a predominance of neutrophil cells 5.
• The values of total protein in pleural effusions vary, and the LDH effusion/sera ratio is often bigger than 0.6 5.

Diagnosis and Treatment

• Spiral computed tomography pulmonary angiography (CTPA) is the best way to evaluate the possibility of pulmonary embolism in a patient with a pleural effusion 3, 4.
• The treatment protocol for a patient with pleural effusion secondary to pulmonary embolism is the same as that for any patient with pulmonary embolism 4.
• Anticoagulant therapy can be administered even in the presence of bloody pleural fluid 4.