Multiple Micro-bone Formation in the Lung of a Patient with Diffuse Interstitial Pneumonia (Fibrosing Alveolitis)

Abstract

An autopsied case of multiple micro-bone formation in the lung of a patient (74 year-old, male) with diffuse interstitial pneumonia was presented. About a year passed from the onset of the disease to death. The honeycomb appearance was noted on the cut surfaces of both lower lobes. Advanced fibrosis and destruction of the lung were marked histopathologically. Numerous micro-bones with bone marrow were seen in alveolar spaces of both lungs, particularly of the right mid and lower lobes. The bones were too small to be seen radiologically. Cardiac abnormality was not detected. The mechanism of ectopic bone formation was discussed.