Pneumocystis pneumonia can complicate medical treatment of hypercortisolism even in outpatients with Cushing's disease

Abstract

Several cases of Pneumocystosis pneumonia (PCP) have been reported in patients with hypercortisolism, mainly in patients with severe ectopic ACTH syndrome (EAS). We report 2 cases of PCP that did not develop until after starting treatment with metyrapone, one of which occurred in an outpatient with Cushing's disease (CD) without pulmonary symptoms before medical treatment for CD. Patient 1 presented as an outpatient with CD and severe hypercortisolism but nonetheless in good general condition. Treatment with metyrapone was started before pituitary surgery. Patient 2 had EAS due to prostate cancer. Respiratory failure in the two patients occurred 4 days and 30 days, respectively, after the start of metyrapone treatment. In both cases, chest CT showed bilateral interstitial infiltrates, and Pneumocystis jirovecii was found on bronchoalveolar lavage (BAL). A literature review was performed to identify risk factors for PCP in patients with CD: we identified 20 other cases of PCP in patients treated for hypercortisolism, including 16 patients with EAS. Ninety percent of patients had free urinary cortisol greater than 6 times the upper limit of normal (ULN). In conclusion, onset of PCP after initiation of anticortisolic therapy is not limited to patients with EAS, and may occur in CD patients with elevated cortisol levels, even if the patient remains in good general condition and has no pulmonary symptoms before treatment. In such patients, routine prophylactic treatment with trimethoprim/sulfamethoxazole (TMP/SMX) should be considered.