An Autopsy Case of Microlithiasis Alveolaris Pulmonum With Special Attention to Elastosis in Lung Tissue—

Abstract

The second autopsy case of microlithiasis alveolaris pulmonum in our country was discussed. This case had no familial back‐ground or genetic predisposition for the disease and followed an almost asymptomatic course for 13 years since abnormal shadow of chest was revealed radio‐logically. Of interest in this case in the deposition observed microscopically of the same substance in alveolar walls or in the interstitium as the ground substance of intra‐alveolar microlith, which was probably responsible for the irregular elastosis.

Pulmonary alveolar microlithiasis

“…The results of analysis of the calcospherites in case 2 were very similar to those of case 1, and are in agreement with analyses reported by Sosman, Dodd, Jones, and Pillmore (1957), Sharp and Danino (1953), and Hotchi et al (1970), confirming the calcified bodies of case 2 to be 'alveolar microliths' despite the unusual histological features.…”

“…They also noted some microliths embedded in an eosinophilic partially collagenized substance resembling an unresorbed, slightly organized exudate, though most were within distended alveolar spaces. A recent report from Japan (Hotchi, Nasu, and Mihara, 1970) drew attention to the presence of nodules in, and thickening of, the alveolar septa, in a case of pulmonary alveolar microlithiasis. Van Gieson elastic staining was reputed as showing the homogeneous nodules to consist largely of elastic fibre and elastoid tissue, but calcification was not mentioned and appears not to have been present in the nodules.…”

“…Case 2 then may represent a further stage in development of this aspect of the disease, with calcification of the ground substance and elastoid tissue within tissue spaces to form microliths. The word 'elastoid' is taken as a direct quote from Hotchi et al (1970).…”

Electron Microscopic Studies on Pulmonary Alveolar Microlithiasis

“…The report of Hotchi et al (1970) is the only one which stresses the prolifera tion of the elastic fibers in this disease. In the case of the eldest sister of this patient, elastosis was recognized in biopsied lung tissue but was not stressed by li ght Sato (1955) .…”

“…The mode of formation of microliths is also obscure. Moreover, no publication is found concerning the detailed ultrastructure of the disease, though many light microscopic studies have been made (Sharp and Danino 1953;Kent et al 1955;Portnoy et al 1964;Hotchi et al 1970). Recently, we had an opportunity to observe the clinical course of a case of this disease.…”