Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Cryptococcosis in immunocompetent host
- Radiologic Findings
- Initial chest radiograph (Fig. 1) shows poorly defined opacity in right apical lung. Chest CT scan (Fig. 2, 3) shows lobulating contoured nodule with internal cavity and surrounding linear densities on RUL. Brain MRI shows multiple ring-enhancing lesions with vasogenic edema in cerebellum, right temporal, both frontal and left perirolandic area.
- Brief Review
- Pulmonary infection with Cryptococcus neoformans can be aymptomatic and subclinical, mild and self-limited in immunocompetent hosts. When symptoms do occur they are usually indolent, progressing over a course of weeks to months. In most cases, patients with pulmonary cryptococcosis do not become symptomatic until pulmonary lesions have become very large. As a consequence, many cases are found incidentally on chest radiograph or CT.
There are 4 primary patterns of radiographic findings in immunocompetent hosts: pulmonary nodules, fungus collections, cryptococcal pneumonia, and disseminated disease. Approximately one third to one half of cases of pulmonary cryptococcosis in immunocompetent hosts define by pulmonary nodules, which are usually subpleural, solitary or clustered. Segmental pneumonia, miliary nodules, cavitation, lymphadenopathy, and pleural effusions are less common in immunocompetent hosts. The recent report regarding to HR CT manifestations described multiple nodules including surrounding centrilobular nodules without “tree-in-bud” appearance.
Diagnosis can be established based on identification of the characteristic yeast-like organism with capsule in tissue with India ink, silver or mucicarmine stain. Diagnosis of pulmonary cryptococcosis can be established by transbronchial or transthoracic biopsy.
In immunocompetent hosts, the natural history of the disease typically results in spontaneous resolution within 1 to 2 months even in the absence of therapy.
- References
- 1. Murayama S et al. Pulmonary cryptococcosis in immunocompetent patients HRCT characteristics. Clinical Imaging 2004;28:191-195
2. Himmel, J. E. and P. Stark. Cryptococcal pneumonia in an immunocompetent host: radiographic findings. Semin Respir Infect 2003;18: 129-31.
- Keywords
- Lung, Infection, Fungal infection,