Successful Treatment of Multifocal Histiocytic Sarcoma Occurring after Renal Transplantation with Cladribine, High-Dose Cytarabine, G-CSF, and Mitoxantrone (CLAG-M) Followed by Allogeneic Hematopoietic Stem Cell Transplantation

Figure 3

(a) Microphotograph of the histiocytic sarcoma cells. At high magnification, the neoplastic cells from the initial oropharynx biopsy are medium sized to large cells with irregular nuclear contours, delicate nuclear membrane, and abundant pale cytoplasm, consistent with atypical histiocytes (H&E, original magnification 400x). (b) Immunohistochemical features of the histiocytic sarcoma cells. The sarcoma cells are positive for CD68 (b, original magnification 200x), lysozyme (not shown), and CD45 (not shown). Approximately 10% of the sarcoma cells are positive for Ki-67 (not shown).