Describe the histopathologic hallmark of tuberculosis.

The caseation granuloma (also known as tubercle) is the histopathologic hallmark of tuberculosis. This consists of giant cells and epithelioid cells and usually has varying amounts of caseation necrosis. This pattern can also be seen in other infections and is not pathognomonic. Acid-fast bacilli are usually easy to find in the early lesions, but there are very few bacilli once granulomas develop.