Tuberculosis is an infectious disease caused Mycobacterium tuberculosis characterised by formation of caseating granulomas. This condition is common in people living under poverty, overcrowding and those suffering chronic debilitating conditions. On gross inspection of the lungs grey-white inflammatory consolidation areas can be found mainly in the upper lobes. This is called Ghon focus. The central area usually undergoes caseous necrosis. Picture credit: https://webpath.med.utah.edu/LUNGHTML/LUNG029.html