대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Nocardiosis

Radiologic Findings

Chest radiograph shows multiple variable sized (1-5 cm) nodules in both lungs. The nodules have cavitation in them. These lesions were rapidly increased in size. Several small nodules developed newly on follow up chest
radiographs. Multiple cavitary nodules with irregular thick wall are seen predominantly in the subpleural portion of both lungs on HRCT scans. Gadolinium-enhanced T1-weighted MR image of the brain shows several low signal intensity
lesions with enhancing rim.

Brief Review

Most cases of pulmonary nocardiosis are due to Nocardia asteroides infection. Nocardiosis is seen particularly in the patients who underwent immunosupressive therapy, who have received organ transplants and the
patients with chronic illness, other underlying immunologic deficiency, or alveolar proteinosis. In severely immunocompromised patients, disseminated disease including involvement of central nervous system, skin, or bone develops. Brain abscess is the most fatal manifestation of nocardiosis.
The chest radiographic findings are variable. Lobar or multilobar consolidation is the most common. The areas of consolidation are usually large and frequently cavitating. They may be unifocal or multifocal and may be patchy, segmental, or occasionally lobar in distribution. Solitary or multiple, irregular, ill-defined, mass-like densities randomly distributed in the lungs are also frequent. Cavitation may occur in one third to two thirds of cases. Unilateral or bilateral pleural effusions are frequent findings. The rare endobronchial mass caused by nocardiosis may exactly mimic a tumor radiologically and on bronchoscopy.

References

1. Armstrong P, Wilson AG, Dee P, Hansell DM. Imaging of Disease of the Chest, 2nd ed. St Louis. Mosby, 1995:190-192
2. Felgin DS. Nocardiosis of the lung: chest radiographic findings in 21 cases. Radiology 1986;159:9-14
3. Yoon HK, Im JG, Ahn JM, Han MC. Pulmonary nocardiosis: CT finidngs. J Comput Assist Tomogr 1995;19:52-55

Keywords

Lung, Infection, Bacterial infection,