Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Primary Pulmonary Tuberculosis
- Radiologic Findings
- Chest PA shows a lobulated mass at right hilum. We can also see the thickening of right paratracheal stripe. CT scans show 5cm sized mass conglomerated with right paratracheal lymph nodes along right lower lobar bronchus.
- Brief Review
- Primary pulmonary tuberculosis is acquired by the inhalation of air borne organisms. The initial site of lung infection is variable, but often, the middle and lower lung zones are first involved. A focal pneumonitis typically results with subsequent caseous necrosis and lymphatic spread of organisms to hilar and mediastinal lymp nodes. In 90% to 95% of subjects, development of immunity results in healing of the lesions, with development of pulmonary and hilar granulomas. Hematogenous spread of infection also occurs in patients who have primary TB, but these organisms are inactivated as immunity develops.
Radiographically, primary TB was associated with consolidation(50% of patients) that often involved the middle or lower lobes, cavitation (29% of patients), segmental or lobar atelectasis (18% of patients), hilar and mediastinal lymphadenopathy (35% of patients), and military disease (6% of patients). These findings may occur alone or in combination, but in up to 15% of patients who have documented TB, chest radiographs may be normal. Hilar lymph node enlargement is common, particularly in young children.
In most subjects, the primary infection is localized and clinically inapparent. However, in 5% to 10% of patients who have primary TB, the infection is poorly contained and dissemination occurs. Extensive cavitation of the tuberculous pneumonia can occur with endobronchial spread of the infection; rupture of necrotic lymph nodes into the bronchi can also results in endobronchial dissemination. Hematogenous spread can also occur as a result of progressive primary tuberculosis.
- References
- 1. Lee JY, Lee KS, Jung KJ, Han JH, Kwon OJ, Kim J, Kim TS, Pulmonary tuberculosis: CT and pathologic correlation. JCAT 2000;24:691-698
2. Im JG, Itoh H, Han MC. CT of pulmonary tuberculosis. Seminars in Ultrasound, CT and MRI 1995;16:420-434
3. Leung AN, Muller NL, Pineda PR, FitzGerald JM. Primary tuberculosis in childhood: radiographic manifestations. Radiology 1992;182:87-91
- Keywords
- Lung, Infection, Bacterial infection, Tuberculosis,