The Great Imitators: Fungal and Fungal-Like Pneumonias With Pathologic Correlation

Fungal and fungal-like pneumonias are significant causes of morbidity, particularly in immunocompromised patients. These infections are known as the great imitators because their clinical and radiologic presentations often mimic those of more common bacterial pneumonias, leading to diagnostic challenges and delays. Although chest radiography is often the initial imaging modality, CT provides more detailed characterization of fungal pneumonias, although some CT findings remain nonspecific. This Categorical Course Highlight reviews the characteristic CT findings of common fungal and fungal-like pneumonias, specifically aspergillosis, nocardiosis, candidiasis, histoplasmosis, cryptococcosis, and coccidioidomycosis. By correlating imaging features and pathology, this review provides radiologists with actionable insights to improve diagnostic accuracy and guide timely treatment.