Chest Imaging in Systemic Endemic Mycoses

Abstract

Endemic fungal infections are responsible for high rates of morbidity and mortality in certain regions of the world. The diagnosis and management remain a challenge, and the reason could be explained by the lack of disease awareness, variability of symptoms, and insidious and often overlooked clinical presentation. Imaging findings are nonspecific and frequently misinterpreted as other more common infectious or malignant diseases. Patient demographics and clinical and travel history are important clues that may lead to a proper diagnosis. The purpose of this paper is to review the presentation and differential diagnosis of endemic mycoses based on the most common chest imaging findings.

Keywords: blastomycosis; coccidioidomycosis; computed tomography; cryptococcosis; endemic mycoses; histoplasmosis; paracoccidioidomycosis.

Figure 1

(A,B) Axial CT images showing peripherally located solid nodules with ground-glass halo in the upper left lobe, in a patient with acute histoplasmosis infection. (C) Coronal CT image depicts left mediastinal and hilar enlarged lymph nodes (arrow).

Figure 2

Axial CT image in a patient with histoplasmosis shows numerous bilateral and randomly distributed solid nodules, some of them with peripheral ground-glass halos.

Figure 3

Cryptococcosis in a 63-year-old man with clinical history of colon cancer, heavy smoking and cough for 3 months. (A) Axial and sagittal (B) images show an irregular solid mass in the right upper lobe adjacent to the pleura and ground-glass halo.

Figure 4

Acute histoplasmosis infection. (A) Axial CT image depicts a left upper lobe nodule. (B) FDG PET/CT shows avid uptake in the pulmonary infection.

Figure 5

Chronic histoplasmosis infection. FDG PET/CT images show higher FDG activity in a mediastinal draining lymph node (arrow) in (B) than in the left upper lobe cavitary mass (A). The flip-flop fungus sign discloses the benign granulomatous nature of the disease.

Figure 6

Acute histoplasmosis infection. Axial CT images from upper (left image) and lower levels (right image) showing bilateral peribronchovascular consolidations and groundglass opacities, and ill-defined centriacinar nodules.

Figure 7

72-year-old male with acute cryptococcosis. Axial CT images from upper to lower levels (A–D) displaying bilateral consolidations with air bronchograms and multiple nodules.

Figure 8

Chronic histoplasmosis infection. CT axial image depicts a spiculated cavity with thick walls in the left upper lobe.

Figure 9

Subacute invasive aspergillosis in a 35-year-old male with HIV infection. CT axial images from an upper and lower levels (left to right) show an irregular cavitary mass in the right upper and lower lobes transgressing the major fissure.

Figure 10

Diffuse miliary nodules in an immunosuppressed patient with histoplasmosis. Axial CT images from upper and lower levels (from left to right) depict diffuse micronodules randomly distributed in both lungs.

Figure 11

Pneumocystis pneumonia in a patient with acquired immunodeficiency syndrome (AIDS). Axial CT images from upper and lower levels (from left to right) reveal diffuse bilateral ground-glass opacities with some peripheral sparing. Multiple bilateral pneumatoceles of varying size, shape and wall thickness are also visualized.

Figure 12

Imaging findings in different patients with paracoccidioidomycosis. The changes are often bilateral, affecting both central and peripheral lung areas and may predominate in the middle zones. The changes are often combined; however, some patterns may prevail. Imaging findings may include patchy bilateral predominant ground-glass opacities (A), multiple bilateral small nodules (B), bilateral consolidations with associated nodules (C), and a dominant pattern of large bilateral nodules (D).

Figure 13

52-year-old man with paracoccidioidomycosis, presenting with a history of 1 year of shortened of breath that had worsened in the last 20 days. (A) coronal CT and (B) coronal minimum-intensity projection images depict bilateral and symmetrical consolidations and cavitations in a “butterfly wing” pattern, nodules, and ground-glass opacities. CT also reveals tracheal infection, with irregular circumferential thickening of the wall (C). Diagnosis was established by transbronchial biopsy.

Figure 14

39-year-old female with ABPA and asthma. (A) Axial CT image depicts right lower lobe varicose bronchiectasis with mucoid impaction. (B) High-attenuation mucus plugging on CT (arrow): a pathognomonic feature of ABPA.