Radiological presentation of Pneumocystis jiroveci pneumonia mimicking bacterial pneumonia.

To cite: Langevin B, Saleh M. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2016215207 DESCRIPTION Atypical radiological presentations of Pneumocystis jiroveci pneumonia have been previously reported in non-HIV as well as in HIV-infected patients. We present the case of a 64-year-old woman with a history of left upper lobe small cell lung cancer in radiological and clinical remission (most recent CT scan performed 1 week before admission). She had undergone treatment consisting of a combination of chemotherapy and left lung irradiation. She was admitted to our intensive care unit due to rapidly progressive respiratory failure. Her blood count showed severe lymphopenia (250 lymphocytes/mm) most probably due to chemotherapy cytotoxic effect. Chest X-rays showed middle lobe confluent pulmonary infiltrates (figure 1). Lung CT confirmed the unilateral involvement and showed one area of lobar condensation within the middle lobe, mimicking bacterial pneumonia (figure 2). Pneumococcal and legionella urinary antigen tests were negative. Quantitative middle lobe bronchoalveolar lavage fluid culture found no bacterial and no fungal growth in bioMerieux and bio-rad culture media, respectively. Acid-fast bacillus smear and culture were negative. A negative influenza A and B PCR test excluded these viral infections. On the contrary, cycle threshold (Ct) of real-time quantitative PCR for P. jiroveci infection diagnosis was 25 (Ct<28 highly suggests infection according to our laboratory threshold values). Despite appropriate antibiotic treatment with intravenous sulfamethoxazole–trimethoprim combination associated with systemic corticosteroids, the patient died 1 week later.