Hepatic amyloidosis in a cat

A 2-year-old Siamese cat presented with a fatal abdominal haemorrhage. On post-mortem examination, the liver was swollen and contained multiple areas of intrahepatic and capsular haemorrhage. Samples of liver were submitted for histopathology.

Fig 1. H&E section of the liver in which the perisinusoidal spaces are infiltrated and replaced by variable quantities of a pale eosinophilic, amorphous acellular matrix (black arrows) typical of amyloid.
Fig 2. Congo red stain which is used to confirm the presence of amyloid. Amyloid stains an orange-red with Congo-red stain (black arrows) and displays apple-green birefringence under polarised light.

Final Diagnosis

Hepatic amyloidosis

Discussion

Amyloid accumulation within the liver of cats is sporadic and can occur as a primary/familial disease or secondary to chronic inflammatory disease. Affected livers are prone to rupture resulting in haemorrhage which can be fatal. Familial hepatic amyloidosis is known to occur in Abyssinians but is also suspected in Siamese and Oriental breeds. Interestingly, one of the littermates of this young cat was subsequently diagnosed with hepatic amyloidosis consistent with a familial aetiology.