Round opacity as a presentation of pneumocystis jirovecii pneumonia in an HIV-infected patient

We present the case of a human immunodeficiency virus (HIV)-infected patient who arrived at our emergency department with fever, headache and exertional dyspnea. Throughout their stay, a chest x-ray was taken and a rounded opacity in his left lung was observed. CT images showed same abnormality and also ground glass opacities were seen. Symptoms and images strongly suggested a pulmonary infection due to pneumocystis jirovecii, however a presence of a round lesion should always lead to neoplasia being suspected. We empirically started treatment based on trimethoprim and sulfamethoxazole. Once available, flexible bronchoscopy and bronchoalveolar lavage was performed and stained preparations from his respiratory specimens confirmed the diagnosis of pulmonary pneumocystis infection. Finally, after 4?days of antibiotic therapy, an important clinical improvement was documented; a new chest x-ray was performed and the previous rounded opacity was absent. This finding strongly suggested a case of round pneumonia.