RESUMO
Objective To investigate the clinicopathologic features and differential diagnosis of alveolar soft part sarcoma(ASPS).Methods A case of ASPS was studied by HE stain,light microscopic observation,histochemical stain and immunohistochemical stain,and discussed the disease synthetically with the literature.Results The patient was female,23 years old.The lesion was located in the deep skeletal muscles of left buttocks,microscopically,which consisted of round to polygonal tumor cells,showing alveolus and nest arrangement,arounded by stroma containing sinusoidal capillaries,and there were abundant crystals in cytoplasm of the tumor cells,prominent nucleoli and fewer nuclear fission images in the tumor cells.PAS stain was stongly positive.Immunohistochemical stain showed positive expression of myoglobin in tumor cells,and negative expression of Myosin,Desmin,SMA,Vimentin,S-100 protein,EMA and Syn in them.Conclusion ASPS is a rare malignant soft tissue neoplasm,its histogenesis is uncertain,and diagnosed by pathological examine and treated mainly by operation.