Abstract

A case of pulmonary alveolar proteinosis is reported. Most of the alveolar spaces were filled with amorphous deep eosinohilic material which revealed strong positive reaction to periodic acid-Schiff staining. Electron microscopic observation of this material showed numerous lamellar bodies in the alveolar spaces and cytoplasms of alveolar macrophages. A part of them were concentric multilamellated type A lamellar bodies and the other were finger printlike type B bodies. Combined type A and type B lamellar bodies were rarely present. From the above features it is suggested that both type A and B lamellar bodies could be transformed one another and those lamellar bodies may be originated from pulmonary surfactant.

• Keywords: Pulmonary alveolar proteinosis;Lamellar body;