Histopathological examination of excised tumor. (a) Synovial tissue was detected in the margin of this tumor (_*). In the subsynovia, there was a thick fibrous septum and diffuse proliferation of fat tissue (Hematoxylin and eosin, × 20). (b) Diffuse proliferation of fat tissue was also detected in the tumor and atypical lipoblasts were not seen (Hematoxylin and eosin, × 50). (c) A few chondral nodules and a thick fibrous septa were found in the fat tissue (Hematoxylin and eosin, × 10).