Two cases of extramedullary myeloid tumor in patients with continuous remission of acute myeloblastic leukemia.

Myeloid sarcoma is described as tumor mass consisting of myeloblasts or immature myeloid cells, involving extramedullary tissues. It can be initial manifestation of myeloproliferative disorders or relapse of previously treated acute myeloblastic leukemia (AML). We present two patients, one with AML-M2 and the other with acute promyelocytic leukemia (APL)-M3. After remission induced by conventional chemotherapy, which continued for 3 and 10 years respectively, a myeloid sarcoma was diagnosed. Biopsy of a retroauricular tumor formation was made in the first case. The second one was diagnozed after biopsy of a supraclavicular lymph node. In both cases complete laboratory investigation including blood smear, differential counting and flow cytometric analysis of bone marrow were normal. Despite this, the patients received chemotherapy. The APL-M3 patient was treated with radiotherapy to the involved supraclavicular lymph node which was followed by chemotherapy. Three months after radiotherapy bone marrow infiltration and blast cells in the peripheral blood were found. Two years after the diagnosis of myeloid sarcoma the patient died of haemorrhagic stroke. The patient with AML-M2 continued treatment with polychemotherapy.