The radiographic manifestations of chronic Pneumocystis carinii pneumonia

Pneumocystis carinii is an opportunistic pathogen of unsettled taxonomy that is believed to be the etiologic agent responsible for the development of Pneumocystis carinii pneumonia. The disease was first observed in premature and malnourished institutionalized infants in Europe in the early 194Os and late 195Os. No immunologic abnormality was described in these patients, and with the addition of ultraviolet light to hospital nurseries there was almost complete disappearance of this form of the disease [1]. Occurrence in the United States and other countries since 1960 has been sporadic, primarily in infants and adults with congenital or acquired immunologic defects. The radiographic features in both the epidemic and sporadic forms of the disease have been extensively reported [2-11]. It is usually seen as a bilateral, diffuse, and rapidly progressive coalescing pneumonitis with a predominantly alveolar pattern [2-5]. Often there is sparing of the lung periphery including the apices [3, 5, 7]. Cavitation has been reported in only one case [4]. Other abnormalities such as pleural effusion, hilan adenopathy, pneumothorax, and pneumomendiastinum are rarely seen in the sporadic form. The following case is reported because of two atypical features-chronicity and cavitation.