A Case of Multiple Myeloma with Auer Rod-Like Inclusions in Plasma Cells

Auer rods are considered to be a distinctive feature of acute myeloid leukemia, presenting in the cytoplasm of leukocytes in a purplish-red rod-like, wood-bundles-like, and spindle-like morphology. In this paper, we report a rare presence of wood-bundles-like Auer rods in the plasma cells of patient with multiple myeloma (MM).

Retrospective analysis of the clinical presentation and laboratory diagnosis of patients with multiple myeloma containing Auer rod-like inclusions in plasma cells were reviewed in this study.

In 2014, 15% of plasma cells were shown in the patient's bone marrow smear, and the diagnosis of multiple myeloma was considered. The cytosol of plasma cells was medium-sized, the nucleus was deviated, the chromatin was aggregated in clumps, and Auer rod-like inclusions arranged in woody bundles were seen in the cytoplasm. In 2017, the patient's condition relapsed, and an abnormal increase of κ-type free light chains was found in the urine, and the urine Bence-Jones protein was positive. In 2021, the patient's condition aggravated to the point of death.

In this uncommon case, the source and mechanism of Auer rod-like inclusions production should be paid more attention to provide rational suggestions for clinical diagnosis.