An additional tumor biopsy was performed six months after the first biopsy, and the histopathological diagnosis was revised to extraskeletal myxoid chondrosarcoma based on the clinical course; immunostaining, which was positive for vimentin, CD56, and S-100; and FISH examination, which was negative for the EWSR1 split signal. The gene discussed is NCAM1; the disease is neoplasm.