Background: The co-occurrence of myeloid sarcoma (MS) and acute promyelocytic leukemia (APL) is a rare clinical event.
Methods: A 56-year-old man presented with lower extremity paralysis that occurred 6 hours before admission. Magnetic resonance imaging revealed an epidural mass.
Results: Histopathological examination demonstrated an extramedullary myeloid malignancy. Bone marrow examination showed abnormal promyelocytes and dysplasia, and an immunophenotyping study indicated very strong myeloperoxidase activity, suggesting APL.
Conclusions: The final diagnosis given was spinal MS with a ZBTB16-RARα variant of APL. The possibility that patients with rapidly progressive neurologic symptoms could have MS and concurrent APL should be considered.