Caseation Necrosis

Caseation Necrosis

The term “caseous” (cheese-like) is derived from the friable yellow-white appearance of the area of necrosis.

Once cause is removed, caseous materials undergo liquefaction slowly and ultimately removed from body.

Caseous necrosis occurs in-

•      Tuberculosis,

•      Syphilis,

•      Ovine caseous lymphadenitis,

•      Actinobacillosis,

•      Actinomycosis etc.

•      Some microbial toxins, e.g., Mycobacterium tuberculosis.

Gross lesions:

•      Necrotic tissue becomes soft, friable and whitish gray materials like ‘milk curd’.

•      It is easily separable with blunt instrument.

•      If there is calcification, there is gritty sound during cutting.

Microscopic lesions:

•      Loss of cell outline and differential staining.

•      Tissue is disintegrated to purple colour granular mass due to mixture of reddish cytoplasm and bluish nucleus.

•      There may be capsulation around the caseous mass.

Significance:

•      The dead tissue may be encapsulated.

•      Dystrophic calcification may occur.

•      Liquefaction may occur at last.

•      It is the indication of some diseases, e.g., tuberculosis.