Giant retroperitoneal lipoma in 62-year-old male: a rare benign tumor in an unusual location.

Lipomas occur elsewhere in the body; however, retroperitoneal lipomas are extremely rare, benign tumors. Unlike liposarcoma, it lacks malignant potential but may grow to a large size because of its spacious retroperitoneal cavity. We report a 62-year-old male presented with progressive abdominal distension for over 2 months. Imaging revealed a large retroperitoneal fatty mass (15.5 × 12.3 × 22.8 cm) herniating through the obturator and sciatic foramina, displacing pelvic organs. Laparotomy with complete excision was performed, and histopathology confirmed a benign lipoma. The patient was discharged without adverse events. Retroperitoneal lipomas are rare and often indistinguishable from liposarcomas on imaging. Histopathology remains crucial for diagnosis, and complete surgical excision provides excellent prognosis, as demonstrated in this case. Differential diagnosis of retroperitoneal masses should include retroperitoneal lipomas, although they are rare. Imaging is useful; however, histopathological examination is essential for definitive diagnosis.