Learning objectives
To present an overview of the spectrum of CT findings in pulmonary aspergillosis.
To correlate the radiologic features with patient’s immune response and with clinical manifestations.
To discuss the main differential diagnoses of the most common forms.
Background
Pulmonary aspergillosis is a mycotic infection caused most of the times by Aspergillus Fumigatus,
an ubiquitous soil fungus acquired by inhaling its spores.
Fig. 1
When we talk about aspergillosis we are referring to a spectrum of radiologic and clinical manifestations that depend directly of the immunological state of the patient and the virulence of the organism.
We can distinguish 4 types of pulmonary aspergillosis.
Aspergilloma (saprophytic aspergillosis)
Allergic bronchopulmonary aspergillosis (ABPA)
Semi-invasive or chronic necrotizing aspergillosis
Invasive aspergillosis (which can be divided into airway...
Imaging findings OR Procedure details
1.
Aspergilloma
Aspergilloma is an Aspergillus infection in immunocompetent host.
The organism causes mild or no reaction and tissue invasion does not occur.
Histopathologically an aspegilloma is a conglomeration of hyphae,
mucin,
fibrin and inflammatory cells in a preexisting pulmonary lesion such as bronchiectasis,
cavity,
bullae or a site of prior surgery.
Fig. 2
The most common underlying causes are tuberculosis,
sarcoidosis and emphysema but it is also possible to find them in patients with bronchiectasis,
pneumoconiosis,
fibrotic lung disease,
neoplasm,
pulmonary infarction,
bronchogenic cyst,...
Conclusion
Aspergillosis is a mycotic infection which produces a wide spectrum of clinical and radiological manifestations that are highly determined by the patient’s immunological status.
Invasive pulmonary aspergillosis is the most severe form and implies a high-rate mortality in immunocompromised patients.
Therapy must be initiated in early stages to be effective and thoracic CT scan is the tool of choice to establish a presumptive diagnosis before serologic and microbiologic tests become positive.
References
Caillot D,
Couaillier JF,
Bernard A,
et al.
Increasing volume and changing characteristics of invasive pulmonary aspergillosis on sequential thoracic computed tomography scans in patients with netropenia.
J Clin Oncol 2001: 19:253-259
Denning DW.
Chronic forms of pulmonary aspergillosis.
Clin Microbiol Infect 2001:7 (Supplement 2): 25-31
Franquet T,
Müller NL,
Giménez A,
Domingo P,
Plaza V,
Bordes R.
Semiinvasive pulmonary aspergillosis in chronic obstructive pulmonary disease: radiologic and pathologic findings in nine patients.
AJR 2000 Jan;174(1):51-6
Franquet T,
Müller N,
Giménez A,
Guembe P,
De...