Specific Forms of Pleuritis

Alvaro C. Laga

Timothy C. Allen

Philip T. Cagle

Eosinophilic pleuritis is characterized by abundant eosinophils in the pleural tissue and fluid. Eosinophilic pleuritis occurs as a reaction to pneumothorax or hemothorax from a wide variety of causes. Other etiologies of eosinophilic pleuritis include drug reactions and infections (tuberculosis, parasites, fungus, certain bacteria). It is commonly identified in patients undergoing pleurectomy and/or excision of blebs and bullae. In these cases, the eosinophilic pleuritis may be associated with bullae or focal honeycombing of the underlying lung parenchyma. In women of child-bearing age, the underlying lung may be affected by lymphangioleiomyomatosis.

Granulomatous pleuritis may be seen in association with infection (tuberculosis or fungus), sarcoidosis, and Wegener granulomatosis. Foreign-body granulomatous reactions may occur in the pleura as the result of iatrogenic instillation of foreign material into the pleural cavity to cause its obliteration for the purpose of treating recurrent pleural effusions.

Histologic Features

Eosinophilic Pleuritis

Infiltrate of eosinophils in the pleural tissue and fluid may include reactive mesothelial cells, histiocytes, lymphocytes, and giant cells.
Adjacent lung may show focal eosinophilic infiltrates within small vessels.
Underlying lung may show bullae, focal honeycombing, or lymphangioleiomyomatosis.

Granulomatous Pleuritis

Areas of granulomatous inflammation or well-formed granulomas with or without central necrosis.
Special stains for organisms, such as Gomori methenamine silver, are helpful when positive but a negative special stain does not rule out infection.
Foreign material such as talc may be identified on polarized light when deliberately instilled into the pleura to cause fibrosis as a treatment for recurrent pleural effusion.