pancreatic lipoma

Pancreatic lipomas are uncommon mesenchymal tumors of the pancreas.

Clinical presentation

Rarely symptomatic, they are most often detected incidentally on cross-sectional imaging for another purpose. If they do cause symptoms, it will typically be those related to regional mass effect from the mass.

Pathology

Mature fat cells with thin internal fibrous septa. It differs from pancreatic lipomatosis in that it has well-defined margins conferred by a thin collagen capsule.

Radiographic features

Correct diagnosis is important to avoid confusion with a neoplastic process. Most contain macroscopic fat.

Ultrasound

• difficult to diagnose: may be hyperechoic or hypoechoic

CT

• well-circumscribed, lobulated lesion in the pancreas
• generally fat attenuation (≤ -30 HU)
• non-enhancing

MRI

• well-circumscribed, lobulated lesion in the pancreas
• T1 and T2 hyperintense
• saturates on a fat-saturated sequence
• may not be hypointense on an out-of-phase sequence (edge may show "india-ink" artefact)

Treatment and prognosis

They are benign lesions, and only rarely require resection.

Differential diagnosis

• pancreatic mature cystic teratoma (dermoid): even more rare; may have associated calcifications
• liposarcoma: should be considered if there are atypical findings such as an infiltrative lesion, a large lesion, or solid enhancing elements
• focal fatty infiltration 
• pseudohypertrophic lipomatosis

Siehe auch:

• Pankreaslipomatose
• Pankreaslipomatose bei Zystischer Fibrose
• benigne Pankreastumoren
• seltene Pankreastumoren
• mesenchymale Pankreastumoren