Immunohistochemical profile of myogenic markers in alveolar soft part sarcoma: a study of ten cases in Tehran

Background: Alveolar soft part sarcoma (ASPS) is a distinctive soft part sarcoma with unknown origin. Recently, myogenic origin was proposed for this tumor. Immunohistochemical studies for myogenic markers reveal contradictory results. The purpose of this study is to determine the histogenesis of alveolar soft part sarcoma by immunohistochemical evaluation of smooth muscle actin, desmin and MyoD1 markers. Methods: Antibodies for myogenin / MyoD1, smooth muscle actin and desmin were employed on ten cases of formalin-fixed, paraffin-embedded alveolar soft part sarcoma. Results: All cases show nonspecific granular cytoplasmic immunostaining with myogenin / MyoD1; nuclei were negative. All Tumors were negative for desmin and smooth muscle actin. Conclusion: Despite the recent interest in the myogenic origin of ASPS there are no definite reasons for it and we could not find any evidence supporting a conclusion of myogenic origin for this tumor, as in many other studies