Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Pulmonary actinomycosis
- Radiologic Findings
- Figs 1. Chest PA shows a huge mass in the left hemithorax and another mass in right upper lung zone.
Fig 2-4. Contrast-enhanced chest CT scan shows a huge multiloculated cavitary mass in the left hemithroax with several foci of septal calcification. Another small mass with similar features is seen at right upper lobe.
Figs 5-7. Previous CT images performed seven years ago.
CT-guided biopsy was performed at left basal lung zone, which revealed the mass to be actinomycosis. Due to the risk associated with extensive surgery, the patient is currently under observation with ampicillin treatment after abscess drainage.
- Brief Review
- Parenchymal patterns of pulmonary actinomycosis include a peripheral pulmonary nodule, mass, or consolidation, all of which may or may not be cavitary or multifocal. Typical CT findings are reported as central areas of low attenuation within the consolidation in 62-75 % of cases and adjacent pleural thickening in 50-73 %. The disease initially manifests as a small, poorly defined, peripheral pulmonary nodule with or without interlobular septal thickening. The pulmonary nodule gradually increases to segmental air-space consolidation, which suggests bronchogenic spread of the disease. If therapy is not adequate, central areas of low attenuation with a cavity slowly develop. Central low-attenuation areas may be multiple and variable in size and show rim-like peripheral enhancement on enhanced CT. Histologically, central low-attenuation areas seen on CT represent microabscesses, which contain actinomycotic or sulphur granules. The peripheral enhancing portion is composed of an outer rim of granulation tissue and fibrosis. The differential diagnosis of the parenchymal type should include tuberculosis, bacterial or fungal necrotizing pneumonia, and lung cancer.
- References
- 1. Han JY, Lee KN, Lee JK, et al. An overview of thoracic actinomycosis: CT features. Insights Imaging 2013;4:245-252.
2. Kim TS, Han J, Koh W, et al. Thoracic Actinomycosis: CT Features with Histopathologic Correlation. AJR 2006;186:225-231.
- Keywords
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Lung, Infection, Bacterial infection,