Pneumocystis carinii: The Spectrum of Diffuse Interstitial Pneumonia in Patients with Neoplastic Diseases

The prospective experience with 18 cases of diffuse interstitial pneumonia in patients receiving immunosuppressive chemotherapy indicates that Pneumocystis carinii is the commonest cause of this form of pneumonia, comprising a minimum of 44% of the cases. A retrospective review of autopsy material of 22 patients dying from diffuse interstitial pneumonia showed a similar frequency. Cases diagnosed as probable or proved viral pneumonia comprised 15% of the total patients. Isolated cases of cryptococcal and toxoplasma pneumonia were noted. Tissue should be obtained to clarify the diagnosis in patients with diffuse interstitial pneumonia. In the proper clinical setting, empirical therapy with pentamidine isethionate should be given to all patients presenting with this form of pneumonia since the prevalence of pneumocystis pneumonia is quite high, and the disease is potentially curable.