Epidural myeloid sarcoma as the presenting symptom of chronic myeloid leukemia blast crisis

Epidural myeloid sarcoma revealing chronic myeloid leukemia is scarce. Herein, we describe a patient that presented with back pain and bilateral sciatica secondary to root compression due to epidural deposition of leukemic cells. The magnetic resonance imaging showed epidural masses, causing a slight restriction of the spinal canal with bilateral L5 root compression. Laboratory examinations showed hyperleukocytosis (white blood cell count: 83 × 109/L, absolute neutrophil count: 60 × 109/L). The bone marrow cytology and immunophenotypic findings confirmed the diagnosis of myeloid leukemia. The diagnosis of spinal myeloid sarcoma revealing chronic myeloid leukemia during the blast phase was established. The patient underwent induction chemotherapy. Then, bone marrow cytology revealed less than 3% of blasts, which correspond to cytological remission. Three months later, MRI showed complete disappearance of the epidural masses. A literature review was conducted by searching PubMed using these terms: "Leukemia, Myeloid" AND "Spine" AND "Sarcoma, Myeloid". We emphasize clinical and radiological findings of spinal myeloid sarcoma. This diagnosis should be considered when the MRI reveals epidural mass lesion. The early management of this disease is necessary, and the treatment of myeloid sarcoma is not codified. Our case highlighted that chemotherapy treatment could be sufficient to lead to the disappearance of myeloid sarcoma and the remission of leukemia.

Keywords: Leukemia; Myeloid sarcoma; Spine.