Ghon ComplexTuberculous Granuloma.
develops in a previously unexposed, and therefore unsensitized, person
immunosuppressed persons may lose their sensitivity to the tubercle bacillus and so may develop primary tuberculosis more than once
lower part of the upper lobe or the upper part of the lower lobe, usually close to the pleura
Ghon focus consisting of coalescent caseating granuloma
Ghon complex: bacilli brought to the hilar LN elicit caseating granulomatous inflammation in the LNs
cell-mediated immunity controls the infection
nidus for reactivation at a later time when host defenses are compromised
Histological appearance of a tuberculous granuloma:
Central Caseous necrosis.
Transformed macrophages called epithelioid cells.
Lymphocytes, plasma cells, and fibroblasts.
Langhans giant cells.
Primary or Ghon’s Complex
Primary tuberculosis is the pattern seen with initial infection. tuberculosis in children.
Reactivation, or secondary tuberculosis, is more typically seen in adults.
Progressive primary tuberculosis:
In Immunocompromised, malnourished children or in the elderly; the primary infection cannot be controlled resulting in continued proliferation of bacilli and destruction of the parenchyma
absence of the characteristic caseating granulomas (nonreactive tuberculosis)
c/f resembles an acute bacterial pneumonia, with lower and middle lobe consolidation, hilar adenopathy, and pleural effusion; cavitation is rare
Lymphohematogenous dissemination- tuberculous meningitis and miliary tuberculosis.