[Atypical morphologic lung manifestations of Pneumocystis carinii infection in AIDS patients]

We report on unusual presentation forms of Pneumocystis carinii infection of the lung in two patients with AIDS. A 36-years-old woman presented a cavitation in the lung middle lobe and bullous changes in the apical portion of the right upper lobe on the chest x-ray. The biopsy of these lesions was not diagnostic and the patient was operated on. The surgical specimen of the removed lung segment showed a cavitary lesion with a border of granulation tissue with giant cells, focal recent and older hemorrhages, rests of fibrinous exudate and dystrophic calcifications. In the surrounding tissue there were Pneumocystis carinii in the alveolar spaces and also in the alveolar walls, this tissue invasion through the organisms being most probably the cause of the cavitary change. A cytomegalic virus infection was also found. A 30-years-old man presented patchy pulmonary infiltrates on his x-ray. The examination of bronchial secretion and bronchial washing specimens revealed P. carinii. In addition, the organisms were demonstrated in the walls of pulmonary vessels and in the stroma of the bronchial mucosa on the biopsy. In a sample of lung tissue which was taken after death, there were no Pneumocystis carinii anymore, but some proliferations of connective tissue with giant cells and calcification, which could represent residual changes of the Pneumocysts carinii infection. Besides, persisting changes of cytomegaly were found. We conclude that a Pneumocystis carinii infection should be considered in all HIV-positive or AIDS patients with any kind of lung lesions.