Case Report: 55 yr old male patient with hx of swelling buttock shows a large fat signal intensity SOL displacing glutei/ involving sciatic foramen with compression of the nerve with a pelvic component with some nodules and septa suggesting well differentiated lipo sarcoma or atypical lipoma.
Teaching points by Dr MGK Murthy , Mr Harinath
Lipoma is very common clinical and radiological finding usually in all locations
Liposarcoma is per say is the commonest soft tissue neoplasm of retroperitoneum
4 varieties of liposarcoma exist
(a) Well differentiated variety shows >75% fat tissue (lipocytes) and broadly resembles Lipoma in Imaging. However can be differentiated by subtle differences like larger size/ broader septa and more nodules .Both show mass effect & do not show enhancement making contrast study redundant .
(b) Myxoid variety , belongs to intermediate grade malignancies ,is the commonest liposarcoma ,shows <10% fatty tissue on histology , on Imaging displays predominantly water signals (T1 and T2 relaxations times similar) with intense and marked enhancement on contrast
(c) Pleomorphic and (d) Round cell varieties contain small amount or NO fat and show heterogenous and less intense enhancement on contrast and belong to high grade malignancies
Atypical Lipoma : MRI
4/ 5Oleh Habifa