Pancreatic Atrophy, Exocrine

AKA Pancreatic Acinar Athropy (PAA)

Pancreatic atrophy (Image sourced from Bristol Biomed Image Archive with permission)

• Degeneration of acinar cells ccurs as a sequel to
  • Starvation - loss of zymogen granules
  • Maldigestion
  • Obstruction of the pancreatic ducts by
    • Neoplasm
    • Chronic inflammation and associated fibrosis
    • Foreign bodies (parasites, pancreoliths
  • Specific nutritional deficiencies include: essential amino acids, zinc, copper, selenium

Clinical signs

• By the time clinical signs of exocrine pancreatic insufficiency (EPI) appear, the pancreas is usually almost totally destroyed
• Chronic diarrhoea with steatorrhoea and undigested muscle fibres. Large quantities of pale faeces are passed (due to dilution of bile pigment and the presence of undigested fats). The faeces have a characteristic rancid or cheesy odour.
• Loss of condition despite marked increase in appetite

Macroscopic appearance

• The pancreas is extremely thin and almost lace-like
• Primarily acinar tissue affected; the ducts and Islets of Langerhans are relatively normal

Microscopic appearance

• In these cases the parenchyma is replaced by atypical parenchyma and adipose tissue
• Irregular, shrunken acini composed of cells with little cytoplasm
• Some cases show a few areas of apparently normal glandular tissue or foci of cellular infiltraton which have been interpreted as suggesting degenerative changes

Aetiology

• The underlying cause is not known, possibly due to nutritional imbalances
• Chronic pancreatitis is a rare cause of EPI
• Possible hereditary EPI in GSDs and rough coated collies

Diagnosis

• Low serum trypsin-like immunoreactivity is an early, preclinical diagnostic test for EPI

• Further Study