Liquid Presenting as Solid: A Rare Presentation of Acute Myeloid Leukaemia as a Solid Epidural Mass.

Myeloid sarcoma (MS) is a very rare malignant tumour composed of myeloblasts. It most commonly involves soft tissue, bone, periosteum and lymph nodes, but unusual presentation sites have also been reported. Typically, MS evolves concurrently with active leukaemia or following remission, when it is known as secondary MS. But rarely MS can occur de novo without evidence of concomitant haematological disease. Herein, we report an unusual case of central nervous system-MS in a patient without evidence of concomitant haematological disease. In this case, progressive thoracic and lumbar pain with paraplegia ultimately led to the diagnosis of acute myeloid leukaemia. We also conducted a PubMed search for case reports, case series and reviews of past literature regarding central nervous system-MS and report our findings. LEARNING POINTS: Myeloid sarcoma (MS) can present de novo in the absence of antecedent leukaemia.Clinical manifestations of neural MS can be variable, including rare ones like spinal cord compression.Timely recognition of MS is paramount, as it is potentially curable. © EFIM 2020.