What does a high leukocyte count indicate when associated with the presence of immunoblastic cells and Auer rods?

A high leukocyte count coupled with the presence of immunoblastic cells and Auer rods is indicative of acute myelogenous leukemia (AML). In AML, the proliferation of myeloid lineage cells results in an accumulation of immature precursors, which can include blasts displaying Auer rods—intracellular inclusions that are pathognomonic for myeloid differentiation. The presence of these features characterizes the acute form of the disease, often leading to symptoms related to the infiltration of bone marrow and other organs due to the high number of immature cells.

In addition to Auer rods, immunoblastic cells present in the leukocyte count can indicate a response to a proliferative process, further supporting the diagnosis of acute myelogenous leukemia, as these cells can emerge during the rapid turnover of hematopoietic cells. Hence, the combination of high leukocyte count, immunoblastic morphology, and Auer rods is distinctly associated with AML, distinguishing it from other leukemias that do not present with these specific findings.