Isolated myeloid sarcoma of lumbar spine without bone marrow involvement: a rare case report and treatment dilemma

Granulocytic sarcoma, chloroma, myeloblastoma, or here referred as myeloid sarcoma (MS), is a rare extramedullary tumor composed of immature myeloid cells called myeloblasts. MS is seen most commonly in patients with acute myeloid leukemia and less frequently in chronic myeloid leukemia, myelodysplastic syndrome. In rarer instances, MS has been shown to precede the development of myeloid tumors by acute myeloblastic leukemia (AML). In particular, isolated MS involving spine is extremely rare. We herein present a rare case of isolated spinal MS in non-leukemic patient. This is a previously relatively healthy 47-year-old man who presented with signs of lumbar spinal cord compression, initially reported as schwannoma on imaging, later diagnosed with spinal MS on pathology. Further workup did not reveal any evidence of bone marrow or other hematological involvement. The patient successfully treated by L4/L5 laminectomy and debulking with subsequent radiation resulting in substantial decrease in size of tumor with significant improvement in symptoms during follow up. This case not only describes a rare case of isolated MS of lumbar spine, but also highlights the potential treatment challenges of such a rare diagnosis. We review the available literature, discuss available treatment options, and highlight the need for further investigations along with increased clinician awareness.