Pulmonary infections in immunocompromised patients: the role of image-guided fine needle aspiration cytology.

Abstract

To evaluate the role of fine needle aspiration cytology (FNAC) in the diagnosis of pulmonary infections in immunocompromised patients and to identify the imaging pattern of infections on computed tomography (CT). This was a retrospective study of 42 immunocompromised patients who underwent FNAC under image guidance owing to a clinical pulmonary infection. Each patient was evaluated for an underlying immunocompromised condition, cytological diagnosis, CT findings and complications. The most common predisposing condition was diabetes mellitus (n = 11), renal transplant status (n = 11) followed by connective tissue disorders (n = 6) and malignancy (n = 5). There were four patients with renal disease and three had a human immunodeficiency virus (HIV) infection. The most common cytological diagnosis was mucormycosis (n = 13) followed by nocardiosis (n = 8) and necrotising inflammation (n = 7), tuberculosis (n = 6), cryptococcosis (n = 2), aspergillosis(n = 2), histoplasmosis(n = 1) and atypical mycobacterial infection (n = 1). Mucormycosis presented as a pulmonary nodule (n = 7), mass lesion (n = 5) or consolidation (n = 4). The patients with nocardiosis had lung nodules with associated consolidation and cavitation. None of the patients had any major complication. FNA is a relatively reliable, safe and quick method of diagnosing pulmonary infection in immunocompromised patients. Cytomorphological features, when aided by special stains, can accurately detect the specific infection which is potentially treatable. Specific infections may be suggested based on specific imaging patterns.