[Granulocytic sarcoma of the femur in a patient with acute megakaryoblastic leukaemia]

Granulocytic sarcoma, chloroma or myeloblastoma are observed in 3% to 7% of acute myeloid leukaemia and represents localized tumour composed of collection of immature leukaemic cells. It appears most frequently in patients with M2, M4 and M5 subtypes of acute myeloid leukaemia

A 58-year-old female presented with pain and oedema of the right upper limb in November 2009. After two months the patinet had fracture dislocation and numerous osteolytic lesions of the right femur. Immunohistochemistry of tumour biopsy showed megakaryoblastic granulocytic sarcoma which was CD31++, F-XIII++, CD34-, FVIII+++, S100-, aktin-, EMA++, Bcl2++, CD43++, with positive proliferative marker measured with Ki-67 positivity in more of 50% of cells. Aspirate of bone marrow and immunophenotyping with flowcytometry revealed diagnosis of acute megakaryoblastic leukaemia. The course of the disease was rapid and the patient died before commencing chemotherapy, five months after first complaints.

Granulocytic sarcoma is extramedullary localization of collection of leukaemia cells which can proceed, to arise concomitantly with leukaemia, or may be the only manifestation of the disease. The diagnosis can be established only with immunohystochemistry.