Pancreatic lipomatosis

Pancreatic lipomatosis refers to the fatty replacement of pancreatic parenchyma. This finding is most often associated with obesity and aging. 

It tends to be the commonest pathological condition involving the pancreas. The condition may occasionally simulate a mass-like lesion particularly when fatty replacement is uneven ¹. 

Pathology

Subtypes

• even pancreatic lipomatosis
• uneven pancreatic lipomatosis ³
  • type 1a: preferential fatty replacement of the head
  • type 1b: preferential fatty replacement of head, neck and body
  • type 2a: preferential fatty replacement of head and uncinate process
  • type 2b: fatty replacement of most of the pancreas except the peribiliary region

Etiology

Systemic

• cystic fibrosis (most common cause in childhood)  
• obesity
• metabolic/endocrine: hyperlipidemia, diabetes mellitus, malnutrition
• storage disease: hemochromatosis
• hepatic disease
• drugs: steroids
• infectious: viral infection, sepsis
• alcoholic hepatitis ⁶
• malabsorption syndrome ⁷

Local

• chronic pancreatitis
• hereditary pancreatitis
• pancreatic ductal obstruction 

Syndromic associations

• Cushing syndrome 
• Shwachman–Diamond syndrome ⁴
• Pearson syndrome (mitochondrial)
• Johanson-Blizzard syndrome ⁴

Differential diagnosis

Imaging differential considerations include:

• pancreatic agenesis: in pancreatic lipomatosis, the ducts remain preserved ³