• amyloid infiltration occurs in all species
  • an inert substance deposited under the endothelium and basement membranes of a variety of tissues

Causes

May be a primary condition or appear secondary to some chronic tissue destructive process

  • an infectious process elsewhere in the body
  • a result of sustained antigenic stimulation, eg repeated injections with an antigenic substance or production of excessive antibody by leukocytes

Gross

  • pale (greyish waxy appearance)
  • enlarged
  • rounded edges
  • firm
  • very prone to rupture

Microscopically

  • deposition of amyloid in the space of Disse
  • shows 'apple-green' fluorescence under polarised light after staining with Congo Red