Granulocytic sarcoma (chloroma): sphenoidal sinus and paraspinal involvement as evaluated by CT and MR.

Granulocytic sarcoma (chloroma) is an unusual tumor composed of primitive cells of the myeloid series. It occurs in younger patients with acute myelogenous leukemia. The lesions present grossly as solid, greenish tumors composed of primitive precursor cells of the granulocytic series. Chloroma refers to the greenish color of the tumor, which can be attributed to the myeloperoxidase in the tumor cells [1]. The tumor may occur before, during, or after the onset of systemic myelogenous leukemia. No sex predilection is noted. Common sites of the tumor include the orbits, skin, bone, and sinuses, with CNS involvement rarely seen. Systemic chemotherapy and local irradiation techniques are being developed for this entity [2], and the frequency with which it is recognized will certainly increase as further reports are made. Radiologic evaluation by CT of the intraand extracranial leukemic infiltrates is well documented in the current literature [1, 3-1 0). Limited reports describe the MR findings of intracranial [6, 11, 12] and paraspinal [13] granulocytic sarcomas. We present two cases of chloroma, one with sphenoidal sinus involvement and the other with a paraspinallesion, that were accurately depicted by MR with CT correlation.