Primary granulocytic sarcoma presenting with bone pain and hypergammaglobulinemia.

Granulocytic sarcoma (GS), is an extramedullary tumorous aggregate of neoplastic myeloid precursor cells, most often associated with acute myeloid leukemia (AML). Primary GS occurs in patients with normal bone marrow and no history of hematological disorders. It is a rare disease, which can involve any organ and mimic other tumors. A correct initial diagnosis, which can be difficult, and early treatment with chemotherapy as for AML patients results in a higher rate of complete remission. We report a case of multifocal primary GS of the bone associated with oligoclonal hypergammaglobulinemia, successfully treated with AML-like induction chemotherapy followed by postinduction therapy with autologous peripheral stem cells transplantation. The possible significance of the associated hypergammaglobulinemia is discussed.