Pulmonary alveolar microlithiasis (PAM) is a rare disease, but in Japan about 60 cases have been reported hitherto, including only one autopsied case. We had the second as an autopsied case.
A 55-year-old male was on March 30, 1967, first admitted to our clinic because of cough and dyspnea which followed a cold. All of his family had good health including his grandparents and his children and there appeared to be no known pulmonary problems in the family. In 1954 he was pointed out the pathologic findings in the chest x-ray accidentally, but no certain diagnosis was made and he had no respiratory symptoms. We could obtain those roentgenograms showing very finely mottled diffuseness of the lesion with greater density toward the bases and the cardiac outlines and diaphragms were indistinct due to the process. These roentgenographic and his clinical course were very suggestive of the PAM.
The roentgenograms of his chest on admission showed far advanced stage of the disease, i.e. in addition to the numerously increased mottled processes there were many thickened linear shadows and those of thickened pleura and emphysematous blebs. In laboratory data decreased vital capacity and PO2 were conspicuous. After leaving hospital on June 3, he was re-admitted for severe dyspnea, it worsened helplessly and he died on October 24, 1967.
On autopsy, the lesion was revealed to be PAM and in lungs adding to the microlith-formation, there were diffuse fibrosis, subpleural emphysematous blebs and the thickening of the pleura and other organs (liver, spleen, kidneys) showed chronic congestion assosiated with chronic cor pulmonale.
Histologically, except for the intraalveolar microliths, ossification and remarkable elastosis in the interalveolar septa were revealed in the lungs.
Chemical analysis of the microliths obtained showed that the predominant elements are calcium and phosphorus (85%) with traces of alminium and iron.
This case belongs to those which have revealed to be of very long course and to progress very slowly without any specific symptoms.
