Granulocytic sarcoma of breast: an aleukemic presentation.

Granulocytic sarcoma is a rare extramedullary tumor composed of immature myeloid cells. It is usually associated with leukemia or other myeloproliferative disorders but can also occur without overt hematologic diseases. The breast is an uncommon site of presentation and requires a high index of suspicion for diagnosis. We report such a case in a 45-year-old female, who presented with nontender left breast lump of 6 months' duration. A peripheral smear and bone marrow examination at that time was normal. A lumpectomy was done. An H and E diagnosis of lobular carcinoma vs. non-Hodgkin's lymphoma was entertained. Immunostains, however, revealed myeloperoxidase, naphthol AS-D chloroacetate esterase and CD43 positivity, indicating a diagnosis of granulocytic sarcoma. It appears that early initiation of systemic AML-type chemotherapy is beneficial and may delay or avert the development of AML in bone marrow and blood. Eight months later, the patient presented with an orbital mass; bone marrow and peripheral smear involvement by AML.

CD43 cross-linking increases the Fas-induced apoptosis through induction of Fas aggregation in Jurkat T-cells

CD43 (sialophorin, leukosialin) is a heavily sialylated surface protein expressed on most leukocytes and platelets including T cells. Although CD43 antigen is known to have multiple and complex structure, exact function of CD43 in each cell type is not completely understood. Here we evaluated the role of CD43 in Fas (CD95)-induced cell death in human T lymphoblastoid cell line, Jurkat. Crosslinking CD43 antigen by K06 mAb increased the Fas-mediated Jurkat cell apoptosis and the augmentation was inhibited by treatment with caspase inhibitors. Further, CD43 signaling of Jurkat cells induced Fas oligomerization on the cell surfaces implying that CD43 ligation have effects on early stage of Fas-induced T cell death. These also suggest that CD43 might play an important role in contraction of the immune response by promotion of Fas-induced apoptosis in human T cells.