Granulocytic sarcoma simulating 'nonsecretory' multiple myeloma

A case of granulocytic sarcoma without the peripheral blood findings of myelogenous leukemia is described. The patient was a 33 year old male who developed numerous osteolytic lesions. On the basis of examination of bone marrow material, an initial diagnosis of "nonsecretory" multiple myeloma was made. Subsequent studies by electron microscopy and enzymatic histochemistry revealed the neoplastic cells to be composed of early myelogenous precursors indicative of granulocytic sarcoma.