Acute Myeloid Leukemia Transformation from Myelofibrosis Upon Remission of an Orbital Myeloid Sarcoma – A Case Report

PURPOSE: To report a case of an orbital myeloid sarcoma concurrent with JAK2 mutation myelofibrosis, which rapidly transformed into acute myeloid leukemia upon aggressive treatment. RESULTS: A 51-year-old woman had progressive swelling of periorbita for one month. Magnetic resonance imaging demonstrated a well-defined, mild enhanced mass indenting the adjacent right lateral rectus muscle and the globe. Biopsy from anterior orbitotomy revealed an orbital myeloid sarcoma. Bone marrow study showed concurrent myelofibrosis. Although the orbital lesion subsided remarkably under aggressive chemotherapy and radiotherapy, the leukemic transformation was noticed in the third month following the initial presentation. CONCLUSION: This case demonstrated that myeloid sarcoma should be included in the differential diagnosis of orbital diseases, with or without involvement of hematological disorders. Early diagnosis and aggressive treatment as for AML are crucial as the prognosis is usually poor for adult orbital MS.