Granulocytic sarcoma of the clavicle.

Acute myeloblastic leukemia is suspected usually because of abnormalities of the peripheral blood or bone marrow. In some cases there may also be an extramedullary focus of leukemic cells called a chloroma or granulocytic sarcoma. On occasion, these tumor masses may precede any evidence of leukemia by months or years. They are often misdiagnosed as lymphomas or granulomas. We present here a case of acute myeloblastic leukemia that was preceded by a granulocytic sarcoma of the clavicle. The initial biopsy of the clavicle was thought to be consistent with Ewing's sarcoma. The patient was treated with systemic chemotherapy prior to gross marrow involvement. He has been in continuous complete remission 34 months after the start of chemotherapy and 44 months after the development of granulocytic sarcoma.