Objective:

To report a case of rapid progression from therapy-related myelodysplastic syndrome (t-MDS) to acute myeloid leukemia (t-AML) following CAR-T cell therapy in a patient with refractory diffuse large B-cell lymphoma (DLBCL).

Approach:

• Case Presentation: A 76-year-old woman with refractory DLBCL developed persistent pancytopenia after CAR-T therapy, leading to a diagnosis of t-MDS and subsequent progression to t-AML.

Key Findings:

• The patient exhibited persistent transfusion-refractory cytopenia post-CAR-T therapy, characterized by severe thrombocytopenia.
• Bone marrow evaluation revealed multilineage dysplasia, 13% blasts, and TP53 deletion/mutation, confirming a diagnosis of therapy-related myelodysplastic syndrome (t-MDS).
• Within two months, the condition progressed to acute myeloid leukemia (t-AML) with 35% abnormal myeloid blasts.

Interpretation:

Persistent post-CAR-T cytopenia may indicate an underlying therapy-related myeloid neoplasm.

Limitations:

• The case is based on a single patient, which limits the ability to generalize findings to a broader population.
• There is a lack of long-term follow-up data on the patient's response to treatment.

Conclusion:

Bone marrow surveillance is important in patients with extensive prior exposure to cytotoxic therapies.