Tuberculosis

Cavitary lesion CXR

Cavitary lesion CT

Infection caused by Mycobacterium tuberculosis

Primary TB

• Initially presents as a homogeneous opacity without lobe predominancy and hilar lymphadenopathy in young
• Results in Ghon complex which may or may not calcify and prominent hilar lymph nodes (Ranke)
• 95% clinically silent

Post Primary TB

• Reactivation
• Pneumonia of the apical or posterior segments of the upper lobes
• May cause cavitation
• Lymphadenopathy uncommon
• Often asked to assess stability which is difficult without comparison (6 months)

Milliary TB: <3mm diffuse nodules, results from hematogenous spread.

Rasmussen's Aneurysm: mycetoma in a TB cavity erodes an artery causing massive hemoptysis

HIV Related

• If CD4 count >200 acts like others
• If CD4 count <200 get Milliary TB, LAD without airspace disease
• Can appear to worsen on HAART, due to body's response