Isolated meningeal chloroma (granulocytic sarcoma) in a child with acute lymphoblastic leukemia mimicking a falx meningioma

Background: Isolated chloromas (granulocytic sarcomas) are rare tumors. Chloromas are masses composed of immature granulocytic cells. Granulocytic sarcoma occurs primarily in patients with acute myelogenous leukemia, but can also arise in patients with other myeloproliferative disorders, though rarely in patients with acute lymphoblastic leukemia (ALL). When dural-based, granulocytic sarcoma may be indistinguishable from meningioma radiologically. Case history: We now describe one patient affected by ALL with isolated granulocytic sarcoma mimicking meningioma as initial CNS relapses. A 12-year-old girl who had been diagnosed with ALL and undergone chemotherapy presented with generalized tonic-clonic seizure while in complete remission. Computed tomographic scan and magnetic resonance imaging showed a small mass mimicking a meningioma at the anterior falx. The patient was developed speech disturbance 6 days later. Follow-up magnetic resonance imaging demonstrated a rapidly growing mass with intralesional hemorrhage. Bone marrow biopsy and cerebrospinal fluid study were negative for leukemia. The patient underwent open surgery. The pathological diagnosis was acute lymphoblastic leukemia. Conclusions: These unusual clinical manifestations and radiological findings in acute lymphoblastic leukemia should be regarded as a recurrence of leukemia. Early detection and antileukemic treatment of granulocytic sarcoma are necessary and important for a favorable prognosis.