We report a rare case of dedifferentiated liposarcoma with malignant granular cell tumor-like elements, this condition has not been previously reported. An 84-year-old woman had a large abdominal mass. CT and MRI examinations denmonstrated the presence of two masscs, both of which were subseguently excised. One of masses was a well-differentiated liposarcoma in the mesentry, whereas the other was a dedifferentiated liposarcoma that displayed dedifferentiation resembling a malignant grarnular cell tumor in the retroperitoneum, upon pathological examination. The latter mass was finally diagnosed as a late complication of a preexisting well-differentiated liposarcoma, not as de novo lesion, because of the coexistence of a component of well-differentiated liposarcoma.