Spinal Extramedullary Hematopoiesis Causing Spinal Cord Compression in Radiation-induced Bone Marrow Aplasia: A Case Report.

In rare cases with no clinical practice guidelines available, the approach heavily relies on small studies, reports, and professional experience based on sound clinical judgement from available data. We present a case of a 52-year-old male radiation technologist with a 5-year history of pancytopenia diagnosed with radiation-induced marrow aplasia after presenting with bilateral lower extremity weakness and numbness. MRI revealed spinal EMH along T3 to T12. He was given steroids and radiation therapy (RT) of 18Gy in 10 fractions with improvement in sensory status at 4^th session of RT and was discharged with steroid on tapering and maintenance of eltrombopag. BM aplasia following chronic low-level radiation exposure results from the accumulation of cytogenetic abnormalities over time. EMH is a compensatory mechanism for BM aplasia, the diagnosis of which is established by MRI. In spinal EMH, transverse myelopathy occurs from spinal cord compression (SCC). As of writing and with our literature-search, spinal EMH has never been reported in patients with aplastic anemia or radiation-related BM aplasia. With the paucity of available data, there is currently no specific guidelines in managing BM aplasia from radiation and consequent SCC. However, as with most cases of SCC, radiotherapy, steroids, and surgical decompression are viable options. This case report will add to the very small pool of information on EMH from radiation-induced BM aplasia and its approach to management especially in this rare, never-before-reported presentation.