We report here a case of primary granulocytic sarcoma that involved multiple organs simultaneously and simulated clinical features of lymphoma at initial presentation. A 55 year-old man was referred to our center for the treatment and evaluation of lymphoma, which was diagnosed for nasal and colonic polyps in a local hospital. In our center, brain MR imaging showed multiple soft tissue lesions in brain and the whole body PET demonstrated multiple hypermetabolic lesions. Immunohistochemical staining of biopsy specimen on nasal and colonic polyp showed negativity of all lymphoma markers and positivity of myeloid markers, and final pathologic diagnosis was granulocytic sarcoma. Cytogenetic analysis of malignant cells in CSF showed chromosomal abnormalities of t(16;16)(p13.1;q22). Bilateral bone marrow examination was done with no evidence of abnormal cell infiltration and with normal cytogenetics. Complete remission was induced with 5 cycles of anti-leukemic chemotherapy, intrathecal chemotherapy and whole brain irradiation. However, leukemia relapsed in blood and bone marrow three months after the completion of treatment and the patient died 11.5 months after initial diagnosis of primary granulocytic sarcoma. In conclusion, immune-histochemical staining is necessary to obtain accurate pathologic diagnosis of granulocytic sarcoma. Pathogenetic role of t(16;16) in granulocytic sarcoma should be evaluated and appropriate treatment of primary granulocytic sarcoma should be defined in the future studies.

Keywords: Primary granulocytic sarcoma, Immunohistochemical stain, Cytogenetic analysis