Diffusely discordant In-111 WBC/Tc-99m SC bone marrow uptake. A possible chemotherapeutic effect

In-111 WBC scintigraphy in a woman with relapsed acute lymphoid leukemia demonstrated normal uptake of white blood cells by the liver and spleen, but virtually absent bone marrow activity. Tc-99m SC imaging confirmed normal marrow function and distribution. A bone marrow biopsy revealed mildly hypocellular, regenerating marrow without leukemic infiltration. The effects of systemic cytotoxic chemotherapy on marrow reticuloendothelial function may have been responsible for this discordant uptake.