Myeloid sarcoma of the orbit

Granulocytic sarcoma is a tumor composed of granulocytic precursor cells occurring in an extramedullary location. It was first noted in association with acute leukemia in 1893.1 At the time, the term extramedullary myeloid cell tumors and my- eloid sarcoma were applied. Three clinical settings for granulocytic sarcoma in association with myeloprolifer- ative diseases are known: as a precursor of the disease in non-leukemic patients, as a manifestation in established acute myelogenous leukemia (AML), or as a sign of im- pending blast crisis in chronic myelogenous leukemia (CML).2 The leukemic infiltrates develop preferentially in bones, but orbital involvement has been reported. Most cases are described in children.3 We encountered two interesting cases of orbital myeloid sarcoma in our center: one occurring in a 66-year-old female, which is unusual because of the age of the patient, and the other in a 6-year-old male, who was further investigated and showed one of the known translocations in AML which is t(8,21). Other chromosome abnormalities described include t(9, 11) involvment of (lb).4 Neither of these patients, however, showed systemic manifestation of the disease at the time of their initial diagnosis.