AML-424 Intranevraxial Myeloid Sarcoma: A Challenging Relapse Presentation of Acute Myeloid Leukemia

• Published in: Clinical lymphoma, myeloma and leukemia myeloma and leukemia, 2023-09, Vol.23, p.S299-S299
• Main Authors: Constantin, Cristina, Ionescu, Bogdan Octavian, Ghiaur, Alexandra, Vasilache, Didona, Popa, Delia Codruta, Jardan, Cerasela, Dragomir, Mihaela, Coriu, Daniel
• Format: Article
• Language: English
• Subjects: AML; central nervous system; extramedullary disease; myeloid sarcoma
• ISSN: 2152-2650; 2152-2669
• DOI: 10.1016/S2152-2650(23)01058-3

Central nervous system (CNS) involvement is rarely seen in acute myeloid leukemia (AML), particularly in adult patients, but poses significant management challenges. Document CNS myeloid sarcoma (CNS-MS) as a relapse manifestation in adult AML, exploring its clinical features, treatment strategies, and outcomes. A 42-year-old man presented to our clinic with a two-week-long history of fatigue and dizziness. Laboratory studies revealed bicytopenia (hemoglobin 7.3 g/dL, platelet count 24×109/L, white blood cell count 6.7×109/L), peripheral blast cells 2.6×109/L, along with elevated lactate dehydrogenase (1,732 U/L). Bone marrow examination showed a 48% blast cell infiltrate. Immunophenotypic analysis described a 20% monoblast population expressing CD13, CD33, CD15, CD56, CD64, CD35, negative for myeloperoxidase, HLA-DR, CD38, and a 10% myeloblast population positive for CD117, HLA-DR, NG2. Cytogenetic and molecular biology studies revealed the t(8;21)(q22;q22.1) translocation and consequent RUNX1-RUNX1T1 fusion. Treatment followed the standard 7+3 regimen, achieving complete remission. Three consolidation cycles with high-dose cytarabine were administered. Minimal residual disease (MRD) assessment using nested polymerase chain reaction detected a positive MRD after the second consolidation cycle. Four months after the treatment was concluded, while maintaining morphologic remission, the patient presented with intermittent headaches and astasia-abasia. Brain magnetic resonance imaging (MRI) revealed two cerebellar mass lesions and posterior fossa crowding. Over the next days, the patient experienced worsening headaches, cerebellar ataxia, hemiparesis, dysarthria, dysphonia and dysphagia. Repeat MRI showed rapid, significant dimensional progression. A midline suboccipital craniotomy was performed, with surgical tumor ablation. Biopsy revealed blast cells with the same immunophenotype, confirming the diagnosis of CNS-MS. Systemic (FLAG-Ida) and intrathecal chemotherapy were initiated, but subsequent bone marrow examinations showed 12% blasts. Salvage therapy consisted of gemtuzumab ozogamicin, high-dose cytarabine, mitoxantrone and all-trans retinoic acid. The patient achieved the second complete remission, underwent CNS radiotherapy, went on to receive allogeneic stem cell transplantation, and is alive and disease-free five years post-transplant. Intranevraxial MS is a rare and life-threatening complication in the clinical course of patients with AML, emphasiz