Pathology General pathology 65c45245 CD 34 is a tumor marker used for- A Ewings sarcoma B Myofibrosarcoma C Alveolar soft pa sarcoma D Inflammatory myofibroblastic tumor High-Yield Explanation Harshmohan textbook of pathology 7th edition. CD 34 is an immunohistochemical stain for sarcoma i;e, endothelial marker. S100 is the immunohistochemical stain for Ewings sarcoma..