post-primary pulmonary tuberculosis
Post-primary tuberculosis, also known as reactivation tuberculosis or secondary tuberculosis usually occurs during the two years following the initial infection. Reactivation frequently occurs in the setting of decreased immunity and usually involves the lung apex.
Pathology
Location
As explained by high oxygen tension and impaired lymphatic drainage, typically there is involvement of:
- apical and posterior segments of the upper lobe
- superior segment of lower lobe
Radiographic features
CT
Parenchymal disease
- ill-defined patchy consolidation
- clustered parenchymal opacification may give rise to a galaxy sign
- cavitation usually develops within the consolidation
- fibroproliferative disease with coarse reticulonodular densities
- endobronchial spread with "tree-in-bud" appearance, best appreciated on HRCT
- healing results in fibrosis, volume loss and traction bronchiectasis
- lymphadenopathy occurs only in 5% cases
Airway disease
Central airway involvement results in bronchial stenosis which may lead to lobar collapse associated with traction bronchiectasis and mucoid impaction.
Pleural disease
- occurs in a minority of cases (18%)
- small pleural effusion
- pleural thickening
- pleural calcification
Chest wall involvement
Chest wall involvement occurring due to direct extension from pulmonary disease manifests as bone and/or cartilage destruction and cutaneous fistula formation.
Siehe auch:
