Diagnostic Dilemma: A Large Pancreatic Lipoma Initially Misdiagnosed as Liposarcoma on CT Imaging

Abstract Pancreatic lipomas are exceptionally rare benign mesenchymal tumors that may closely resemble well-differentiated liposarcomas on imaging, particularly when large or atypical. We report the case of a 60-year-old man who presented with abdominal pain, nausea, and vomiting, and was found to have a large fat-containing mass in the pancreatic head on computed tomography. Imaging characteristics—including size, mild heterogeneity, and a cystic component—raised strong suspicion for a well-differentiated liposarcoma. Due to diagnostic uncertainty and potential oncologic risk, the patient underwent a pancreaticoduodenectomy (Whipple procedure). Histopathological evaluation revealed a benign pancreatic lipoma composed of mature adipocytes without atypia or lipoblasts. This case highlights the diagnostic limitations of imaging in differentiating benign from malignant fat-containing pancreatic lesions and underscores the essential role of histopathology for definitive diagnosis. Surgical resection remains crucial when imaging is inconclusive or when malignancy cannot be confidently excluded.