Fine structure of granulocytes with cytoplasmic inclusions in pleural effusions from patients with rheumatoid pleuritis, tuberculous pleuritis and pleural carcinomatosis.

The fine structure of neutrophil granulocytes from pleural fluid obtained from patients with rheumatoid or tuberculous pleuritis or epidermoid carcinoma of the lung was identical irrespective of the primary disease of these patients. Homogenously stained lipid-like inclusions were present in the cytoplasm of the neutrophil granulocytes. They seemed to be formed de novo, as they lacked a distinct limiting unit membrane. The fine structure of the lipid-like inclusions gave no evidence to support the presence of immune complexes, these were probably located in the quantitative much fewer phagosomes of the granulocytes.