Histological and immunohistochemical diagnosis of granulocytic sarcomas

Objective:To study the histological features and immunohistochemical diagnosis of granulocytic sarcoma. Methods:The morphological and immunohistochemical featrures were retrospectivelly analyzed in 7 cases of granulocytic sarcoma.Results:Histologically, the GS were composed of a relatively uniform population of poorly differentiated cells growing in a diffuse pattern and were small to medium in size, with scant cytoplasm. The nuclei were round and oval, and had finely dispersed chromatin. Immunohistochemistry study showed that 6 cases were positive for MPO and CD43, 5 cases for CD68, 4 cases for CD 99, 3 cases for CD34 and CD43. Conclusions:Granulocytic sarcomas are morphologically analogous to malignant lymphoma in routine paraffin-embedded tissue sections and may be frequently misdiagnosed. Immunohistochemistry panel of granulocytic makers such as MPO、CD68、CD43、CD34、CD99 can successfully identify the vast majority of GS.