The term caseous means 'pertaining or related to cheese',[4] and comes from the Latin word caseus 'cheese'.

[5][6] On microscopic examination with H&E staining, the area is acellular, characterised by amorphous, roughly granular eosinophilic debris of now dead cells,[6] also containing interspearsed haematoxyphilic remnants of cell nucleus contents.

As the cells die they disintegrate but are not completely digested and the debris of the disintegrated cells clump together creating soft granular mass that has the appearance of cheese.

[9] As cell death begins, the granuloma forms and cell death continues the inflammatory response is mediated by a type IV hypersensitivity reaction.

[10] Some data suggests that the epithelioid morphology and associated barrier function of host macrophages associated with granulomas may prevent effective immune clearance of mycobacteria.