Abstract
Myeloid sarcoma (MS) is a solid mass of myeloid blasts outside the bone marrow (BM). Most cases occur in the setting of intramedullary acute myeloid leukemia (AML), but it can also present in the absence of overt BM disease, as a presentation of newly diagnosed or relapsed AML, or as a progression of myeloproliferative neoplasms or myelodysplastic syndromes. There are a few reports of spinal cord compression due to MS, and there is no consensus regarding its management. Here, we present a case of relapsed AML in the form of MS resulting in spinal cord compression and provide a comprehensive literature review of previously reported cases of MS causing cord compression. An 18-year-old male was diagnosed with AML with poor-risk cytogenetics in September 2023. He received induction chemotherapy (CTX) with 7+3, followed by consolidation with high-dose cytarabine, achieving remission. He was referred for BM transplant evaluation but opted against it. One year later, he presented with a four-month history of bilateral motor and sensory deficits along with bladder dysfunction. A magnetic resonance imaging (MRI) of the spine showed multilevel nerve root thickening and enhancement and multiple extramedullary masses. Spinal radiation therapy and corticosteroids were given; a biopsy was deferred due to high procedural risks. Given his prior history of AML, the findings were highly suspicious for MS. A complete blood count (CBC) and smear did not show circulating blasts, and a BM exam was inconclusive. Induction CTX with MEC regimen (mitoxantrone, etoposide, cytarabine) was started. A lumbar puncture with CSF flow cytometry confirmed central nervous system involvement with myeloid blasts, and a brain MRI revealed leptomeningeal disease. Intrathecal CTX was given. A spine MRI on day 15 post-induction showed partial improvement in spinal disease. The patient was discharged 30 days after receiving induction CTX, and he planned to continue his care at a local cancer institute in his home state.