Objective:To investigate the Clinicopathological characteristics of extraskeletal myxoid chondrosarcoma(EMC).Methods:Nine cases of extraskeletal myxoid chondrosarcoma were studied.Extensive immunohistochemical analysis was performed in all the cases and ultrastructural studies were done in 2 extraskeletal myxoid chondrosarcomas.Follow-up information was available for seven patients.Results:There were 7 males and 2 females whose ages ranged from 31 to 69 years(median 52.78 years).Local pain or tendess and the presence of a palpable mass were the main complaints of the patients.The tumors were located mainly in the lower extremities(66.7%).Most tumors were deep-seated.They usually had a distinct multinodular configuration delineated by fibrous connective tissue.The tumor cells were arranged in delicate intersecting strands,rings,and garlands for the most part.The myxoid matrix was abundant in most cases.Immunohistochemical analysis was performed in all the cases and ultrastructural studies were done in 2 extraskeletal myxoid chondrosarcomas.EMC expressed vimentin(100%,9/9),neuron-specific enolase(77.8%,7/9),S-100 protein(66.7%,6/9),synaptophysin and chromogranin A(22.2%,2/9).None of the tumors expressed EMA and desmin.Ultrastructurally:EMC was characterized by distinct cords of cells immersed in a glycosaminoglycan rich matrix.The cells were rich in mitochondria,had well-developed Golgi apparatus and there were numerous smooth vesicles.In many cells,there were also prominent glycogen deposits and lipid droplets.Some tumor cells had intracistal microtubules.In one of the 2 extraskeletal myxoid chondrosarcomas there were 140-180 nm diameter membrane-bound dense-core secretory granules in cell bodies.Conclusion:Extraskeletal myxoid chondrosarcoma(EMC)is a rare soft tissue sarcoma characterized by distinctive morphological and cytogenetical features.However,the chondroid nature has been a subject of controversy,and its line of differentiation remains to be determined.A substantial proportion of EMC shows immunophenotypic and/or ultrastructural evidence of neuroendocrine differentiation.EMC has high potential of local recurrence and metastasis,and a high disease-associated death rate.