Pancreatic lipomatosis

Last revised by Arlene Campos on 12 Feb 2025

Pancreatic lipomatosis refers to fat accumulation in the pancreatic parenchyma. This finding is most often associated with obesity and aging and is the most common pathological condition involving the pancreas. Uneven fat deposition can simulate a pancreatic mass 1

Synonyms include pancreatic lipomatosis, fatty pancreas and pancreatic steatosis 8,9. Non-alcoholic fatty pancreas (NAFP) excludes alcohol as a cause. Lipomatous pseudohypertrophy is characterized by pancreatic enlargement and may be a distinct entity 8.

The entity can be divided by etiology 8:

  • fatty replacement: death of acinar cells and subsequent replacement with adipocytes

  • fatty infiltration or nonalcoholic fatty pancreas disease: pancreatic accumulation of adipocytes in association with obesity and/or metabolic syndrome

The majority of pancreatic fatty deposits have no clinical significance. However, excessive fatty deposits may cause loss of pancreatic function, causing maldigestion of nutrients. This may lead to symptoms of chronic diarrhea, steatorrhea and weight loss, without any abdominal pain or signs of diabetes mellitus due to low insulin production 20. Symptomatic fatty pancreas is identified in several case reports 20.

  • even pancreatic lipomatosis

  • uneven pancreatic lipomatosis 3,9

    • type 1a: preferential fatty replacement of the head, sparing the uncinate process and peribiliary region

    • type 1b: preferential fatty replacement of head, neck, and body, sparing the uncinate process and peribiliary region

    • type 2a: preferential fatty replacement of head, including uncinate process, and sparing the peribiliary region

    • type 2b: total fatty replacement of the pancreas except for the peribiliary region

Several etiologies are well established 8:

Less established etiologies include the following 8:

On ultrasound, fatty pancreas has hyperechoic parenchyma 20.

On CT scan, fatty pancreas has hypodense parenchyma 20. On unenhanced CT, the pancreas would show similar density to surrounding retroperitoneal fat (negative attenuation values). On contrast-enhanced CT, pancreatic parenchyma would show higher density (positive attenuation values) due to enhancement of pancreatic parenchyma between fatty infiltration areas 1.

Imaging differential considerations include:

Cases and figures

  • Figure 1: causes of pancreatic lipomatosis
  • Case 1: T2
  • Case 1: T1 out-of-phase
  • Case 1: T1 in-phase
  • Case 2: T1 out-of-phase
  • Case 2: T1 in-phase
  • Case 3: total pancreatic lipomatosis in cystic fibrosis
  • Case 4: presumably result of aging
  • Case 5: Shwachman Diamond syndrome
  • Case 6: pancreatic lipomatosis
  • Case 7: in cystic fibrosis
  • Case 8
  • Case 9: steroid-induced
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