Extraskeletal myxoid chondrosarcoma. A clinicopathologic and immunohistochemical study of two cases

Two extraskeletal myxoid chondrosarcomas arising on the left lower extremity of two women, aged 48 and 72 years, respectively, are reported. One case mimicked clinically an organized hematoma. By light microscopy, they showed a lobular architecture. Anastomosing cords of cells lying in a myxoid background were the histologic hallmark. Based on conventional criteria, they were classified as neoplasms of low (G1) and intermediate (G2) grade malignancy. Both cases were strongly positive for S-100 protein and vimentin. Follow-up confirmed the low aggressiveness of this entity.