Postradiation Histiocytic Sarcoma in the Setting of Muir-Torre Syndrome

Figure 2

Immunohistochemistry was positive for (a) CD 163+, (b) CD14+, and (c) CD4+. CD163 and CD14 are expressed on macrophages, while CD4 is expressed on other cells, such as helper T-cells; CD4 is also expressed on monocytes/macrophages. Immunohistochemistry was negative for (d) CD34. CD34 negativity indicates that this neoplasm is not a myeloid sarcoma.

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