Idiopathic spontaneous pneumothorax. Electron microscopic study

A lung biopsy obtained from a patient following a second occurrence of idiopathic spontaneous pneumothorax was studied by electron microscopy. A remarkable increase in septal mass was a notable finding. Proliferation of the interstitium was due to an abundance of collagen and elastic fibers. In additon, a proliferation of type 1 and type 2 epithelial cells was seen.