primary intracranial granulocytic sarcoma: a case report and review of literature

Granulocytic sarcoma (GS) is a rare extramedullary proliferation of myeloblasts or immature myeloid cells leading to the disruption of normal architecture of tissue in which it is found. It may precede, be concomitant with or appear after diagnosis of acute/chronic leukemia, in acute or relapse setting. Herein, we report a case of 12-year-old male who presented with left-sided hemiparesis. Neuroimaging revealed a space occupying lesion in basal ganglia and thalamus. Stereotactic biopsy with immunohistochemistry (IHC) studies was suggestive of lymphoid malignancy versus GS. However, immunophenotyping (IPT) done on cerebrospinal fluid leukemic blasts was positive for GS. The patient initially received therapeutic cranial radiotherapy with biweekly triple intrathecal chemotherapy followed systemic high-dose cytarabine chemotherapy. Since bone marrow examination failed to reveal any evidence of hematologic malignancy, a diagnosis of aleukemic, primary, or isolated GS of brain was made. Our case emphasizes the importance of early suspicion, diagnostic dilemma associated with GS, the role of histopathology, IHC, and IPT in diagnosis, and various treatment modalities of aleukemic intracranial GS.