CRA90 PNEUMATOCELE OR LUNG ABSCESS IN PNEUMOCYSTIS PNEUMONIA: A DIAGNOSTIC IMAGING DILEMMA

MR Muniandy ^{1, 2} and WA Wan Ahmed ^{1, 2}.

¹ Department of Radiology, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia.
² Hospital Pakar Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia.

Pneumatoceles are thin-walled, air-filled cystic lesions that may develop in various infectious lung conditions. In immunocompromised patients with Pneumocystis jirovecii pneumonia (PJP), distinguishing pneumatoceles from lung abscesses on imaging can be diagnostically challenging, yet critical for appropriate management.

We report a case of a 51-year-old immunocompromised male with newly diagnosed retroviral disease (RVD) and profound low CD4 count, who presented with respiratory failure. Chest radiograph revealed a cavitating lung lesion suggesting of lung abscess, raising concerns for tuberculosis or fungal infection. However, CT features were more consistent with a pneumatocele which most likely secondary to Pneumocystis jirovecii pneumonia.

This case highlights the diagnostic pitfalls associated with overlapping radiologic features of pneumatocele and lung abscess, particularly in the context of Pneumocystis pneumonia. A comprehensive understanding of the radiological patterns, including lesion wall thickness, air-fluid levels, and surrounding lung architecture, is essential in differentiating these entities.

The case also illustrate the importance of integrating clinical, radiological, and microbiological findings to reach an accurate diagnosis and avoid unnecessary invasive interventions.

Keywords: Pneumatocele, Lung abscess, Cavitating lung lesions, Pneumocystis jirovecii pneumonia (PJP).