Granulomatous Pneumocystis carinii pneumonia in patients with malignancy

Background: A review was undertaken of the clinical features and results of diagnostic tests in non-HIV infected patients who developed granulomatous Pneumocystis carinii pneumonia (PCP). Methods: A retrospective review was performed of the charts and radiographs of patients with a granulomatous reaction to P carinii identified from computerised pathology records at Memorial Sloan Kettering Cancer Center, a university affiliated tertiary care hospital. Results: Three cases were identified; the incidence of granulomatous PCP was 3%. All patients had risk factors for PCP and had received high dose corticosteroids which had been stopped. Two patients had received chemotherapy. Presentation was insidious with only mild symptoms; only one patient had fever. Chest radiographs showed a reticulonodular pattern. Bronchoscopy was negative for PCP in all cases and open lung biopsy was necessary. Conclusion: A granulomatous pathological reaction to PCP occurs rarely in patients with malignancy. In these cases the clinical presentation may be atypical and bronchoscopy can be non-diagnostic.