Massively diffuse multifocal granulocytic sarcoma in a child with acute myeloid leukemia.

: A case of granulocytic sarcoma in an 8-year-old boy with acute myeloid leukemia and t (8; 21) is reported. The case is of interest due to massive extension of the tumor, which may raise different diagnostic difficulties with other solid tumors such as lymphoma, Ewing sarcoma, and soft tissue sarcoma. Furthermore, the tumor was localized in some sites, such as the parotid region and peripheral nerves, which are not usually involved in granulocytic sarcoma. The case points out the diagnostic difficulties with this kind of tumor and appears to contribute to the identification of a subgroup of acute myeloid leukemia with peculiar features, such as M2 morphology with Auer rods, t (8; 21), granulocytic sarcoma and a poor prognosis.