[Granulocytic sarcoma developing in lymph nodes].

A 77-year-old man was admitted to a hospital because of a left cervical tumor. He was initially diagnosed as having non-Hodgkin lymphoma, diffuse large cell type, Ann Arbor stage IV, and transferred to our hospital for chemotherapy. Flow cytometric analysis of the left axillary lymph node cells derived from a biopsy specimen showed that in addition to lymphoid surface markers (CD5, 7, 21), myeloid surface markers (CD11b, 33, 34) were also positive. The diagnosis of malignant lymphoma was therefore confirmed. The patient, was treated with THP-COP therapy, which proved very effective. Thereafter, a biopsy specimen was found to be positive for MT1 (CD43) staining but negative for myeloperoxidase and chloroacetate esterase staining on immunohistochemistry. Furthermore, no rearrangement of the IgH JH, TCR C beta 1 or TCR J gamma gene was detected by Southern blot analysis. On basis of these findings and the previous results of flow cytometry, we changed the diagnosis from malignant lymphoma to granulocytic sarcoma. THP-COP therapy was continued, and complete remission was achieved. Two months later, however, the patient developed acute myelocytic leukemia (AML M1) and received DCP therapy, but he died of pneumonia.