대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Actinomycosis

Radiologic Findings

Figures 1-3. Chest CT shows variable sized solid nodules in BUL and LLL.

Brief Review

Pathologic result of percutaneous needle biopsy of the lung nodule was chronic active inflammation with actinomycosis colonies.
Pulmonary actinomycosis has worldwide distribution and has no age or race predilection, although men acquire the disease slightly more often than women (in an approximately 3:1 ratio), and children are rarely affected. The clinical manifestation of the disease has changed to a less aggressive form compared to the pre-antibiotic era. The usual presentation is now an indolent, slowly progressive pneumonia with fever, weight loss, cough, sputum and chest pain. The symptoms and clinical and radiologic signs mimic malignancy or tuberculosis.
Parenchymal patterns of pulmonary actinomycosis include a peripheral pulmonary nodule, mass or consolidation, all of which may or may not be cavitary or multifocal. In an early stage of infection, the disease manifests as a small, poorly defined, peripheral pulmonary nodule with or without interlobular septal thickening. With the slow progression of infection, the pulmonary nodule gradually increases in extent to manifest as an air-space consolidation or a mass. Central low-attenuation areas may be multiple and variable in size and show rim-like peripheral enhancement on enhanced CT.
The principal treatment of actinomycosis is long-term use of high-dose intravenous penicillin. The course of the disease depends largely on adequate and early antibiotic therapy.

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