Chronic Cough and Severe Weight Loss in a 55-Year-Old Previously Healthy Man

(See page 348 for the Photo Quiz.) Diagnosis: Pneumocystis pneumonia. Bronchoalveolar lavage fluid (BALF) staining with Grocott-Gomori methenamine silver demonstrated black round cysts of 4- to 6-µm diameter, suggesting a possible infection with Pneumocystis jirovecii (Figure 1), which was confirmed by positive immunofluorescence assay and by the detection of Pneumocystis-specific DNA using real-time polymerase chain reaction (PCR) from BALF. Later the patient tested positive for human immunodeficiency virus (HIV) type 1 with an RNA load of 183.33 copies/mL and a CD4+ T-cell count of 28 cells/µL. Black cysts of Pneumocystis jirovecii in the bronchoalveolar lavage fluid cell pellet after centrifugation (Grocott-Gomori methenamine silver staining). Medical treatment, including intravenous trimethoprim- sulfamethoxazole (TMP-SMX) 5760 mg (20 mg/kg/day TMP) in 3 divided doses for 21 days, followed by prophylactic dosage of TMP-SMX 960 mg once per week and antiretroviral therapy (ART) with atazanavir 300 mg once per day, ritonavir 100 mg once per day, and tenofovir/emtricitabine 254/200 mg once per day, was initiated. After 3 months of ART, follow-up computed tomography scan showed a remarkable radiological improvement and the patient’s symptoms had resolved completely (Figure 2A and 2B; Supplementary Video 2). A and B, Matching follow-up computed tomography of the chest after 3 months of initial trimethoprim-sulfamethoxazole treatment for 21 days and continuing antiretroviral treatment, showing almost complete resolution of the lesions (see Supplementary Video 2). Radiological features of pneumocystis pneumonia (PCP) are highly variable depending on the underlying disease and host immune response. Bilateral ground glass opacities are the most common radiological pattern [1, 2]. Although pulmonary cysts can be associated with PCP [2, 3], especially in patients with AIDS, the name pneumocystis refers to the microscopic image of the fungus and not to the radiological pattern of the disease [4, 5]. HIV-infected patients experience a milder disease severity and often stay undiagnosed for weeks or month, resulting in a chronic pulmonary inflammatory response to the pathogen with cystic destruction of lung parenchyma [6]. In immunocompromised HIV-uninfected patients with PCP, cystic-like lesions are usually absent [2]. These patients commonly experience a more progressive disease development within days and have a higher mortality [2, 7]. Cystic lesions in PCP can vary in shape, size, distribution, and wall thickness, but are usually multiple with a thin wall and located bilaterally, often with an upper lobe predominance [8]. Complication of pneumothorax emerges in up to 35% of cases and is sometimes difficult to manage because of persistent air leaks when treated with a chest tube [8]. Complete resolution of cysts can be achieved in up to 46% of cases after appropriate treatment with TMP-SMX [8, 9]. With the early introduction of ART and the widespread use of TMP-SMX chemoprophylaxis, the frequency and mortality of PCP decreased significantly [10, 11]. As a consequence, prominent manifestations of PCP are becoming rare and are purely seen in HIV late presenters or HIV patients with poor treatment adherence [12]. Our case report should recall awareness of this rare radiological pattern as a characteristic manifestation of PCP in high-risk populations. Some characteristics have to be considered. First, large cystic lesions in previously healthy individuals should always include PCP in the differential diagnosis, raising the question of immunosuppression including the HIV status of the patient. Second, diagnosis is generally made by visualization of cysts or trophic forms in BALF (eg, Grocott-Gomori methenamine silver or immunofluorescent staining) demonstrating high rates of sensitivity between 89% and 98% [13]. Third, high risk of developing a pneumothorax has to be kept in mind. Fourth, appropriate dosing of TMP-SMX is always related to the TMP component and should be 15–20 mg/kg/day TMP for 21 days (with the addition of corticosteroids in moderate to severe cases) [14]. Fifth, appropriate treatment is highly effective, resulting in high rates of partial or even complete resolution of pulmonary cysts. Supplementary materials are available at Clinical Infectious Diseases online. Consisting of data provided by the authors to benefit the reader, the posted materials are not copyedited and are the sole responsibility of the authors, so questions or comments should be addressed to the corresponding author. Potential conflicts of interest. C. He. has received personal fees from Janssen, Genzyme, and Hexal.