From the Guidelines
Pancreatic liposubstitution seen on a CT scan is associated with several conditions, primarily pancreatic atrophy and exocrine pancreatic insufficiency, and requires prompt evaluation and management to prevent nutritional deficiencies and improve quality of life. This finding represents the replacement of normal pancreatic tissue with fat, which occurs when functional pancreatic tissue is lost and replaced by adipose tissue. Common conditions associated with pancreatic liposubstitution include:
- Chronic pancreatitis
- Cystic fibrosis
- Diabetes mellitus (particularly long-standing type 1 diabetes)
- Advanced age
- Severe malnutrition The degree of fatty replacement often correlates with the severity of exocrine pancreatic dysfunction, as noted in the 2023 expert review on the epidemiology, evaluation, and management of exocrine pancreatic insufficiency 1.
Patients with significant pancreatic liposubstitution may require pancreatic enzyme replacement therapy (PERT) such as pancrelipase (Creon, Zenpep) at doses of 25,000-40,000 lipase units per meal, adjusted based on symptom response and nutritional status, as outlined in the US Food and Drug Administration–Approved Formulations of Pancreatic Enzyme Replacement Therapy 1. PERT helps manage symptoms like steatorrhea, weight loss, and malnutrition that can accompany exocrine insufficiency. The presence of liposubstitution should prompt evaluation of pancreatic function and investigation into underlying causes, as early intervention can help prevent nutritional deficiencies and improve quality of life. Monitoring nutritional status is essential in those with exocrine pancreatic insufficiency, and baseline measurements of nutritional status, including body mass index, quality-of-life measure, and fat-soluble vitamin levels, should be obtained, with a baseline dual-energy x-ray absorptiometry scan repeated every 1–2 years 1.
From the Research
Pancreatic Liposubstitution on CT Scan
- Pancreatic liposubstitution, also known as fatty replacement, can be seen on a Computed Tomography (CT) scan and is associated with various conditions, including pancreatic steatosis 2.
- Pancreatic steatosis is a disease characterized by fat infiltration in the pancreas, which can lead to pancreatitis, diabetes mellitus, and may be a predisposing cause of pancreatic cancer 2.
- Fatty replacement in the pancreas can also be seen in other conditions, such as focal fatty infiltration, teratoma, and liposarcoma 3.
- The detection of fatty tissue on CT scans is an important feature for diagnosing pancreatic lipomas and distinguishing them from pancreatic carcinoma 3.
Diagnostic Challenges
- The presence of pancreatic liposubstitution on a CT scan can make it challenging to diagnose pancreatic cancer, as it can mimic other conditions 4, 5.
- A study found that pancreatic duct dilation proximal to a focal solid pancreatic lesion on CT scan is highly suggestive of pancreatic adenocarcinoma, but it is not a definitive diagnostic criterion 5.
- The use of dual-phase helical CT can improve the prediction of resectability in patients with pancreatic cancer, but it may not detect all cases of vascular invasion or liver metastases 6.
Imaging Characteristics
- On CT scans, pancreatic lipomas typically appear as homogenous, well-circumscribed lesions with macroscopic fat (<-30 HU) 3.
- The density of pancreatic lipomas on CT scans can range from -20 HU to -30 HU, and they are usually located in the pancreatic head, body, tail, or uncinate process 3.
- Magnetic Resonance Imaging (MRI) can also demonstrate fat in pancreatic lipomas, which can aid in diagnosis 3.