Although a myeloid sarcoma is a rare form of extramedullary leukaemia, its early diagnosis has been proven to be of utmost importance. Its presence is strongly related to the onset or the presence of systemic bone marrow leukaemia. However, the diagnosis of myeloid sarcoma is not straightforward. In the existing literature, approximately half of the cases of myeloid sarcoma were initially misdiagnosed as lymphoma. The current case reports details on the laboratory diagnosis of myeloid sarcoma in a 25-year old male. The laboratory presentation of myeloid sarcoma and the consecutive steps in order to correctly diagnose myeloid sarcoma using a variety of laboratory techniques including microscopy, flow cytometry and cytogenetics are highlighted.

(BELG J MED ONCOL 2013;7(4):119–22)