This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
All of the following immunohistochemical markers are positive in the neoplotic cells of granulocytic sarcoma, EXCEPT: 
Select and explain. 
A. CD 45 RO, B. CD 43, C. Myeloperoxidase, D. Lysozome
A: CD 45 RO
Answer: A: CD 45 RO 
Explanation: A variety of markers for myeloid precursors in granulocytic sarcoma are identified. CD43, lysozyme, myeloperoxidase and CD 15 are the most sensitive markers staining a large propoion of the cells of the majority of well-differentiated tumors. CD 45 RO is not mentioned as a immunohistochemical marker of granulocytic sarcoma. Ref: Manual of Diagnostic Antibodies For Immunohistology By Anthony Siew-Yin Leong, Kumarasen Cooper, F. Joel W.-M. Leong, 2002, Page 339.