Spinal extramedullary hematopoiesis mimicking an epidural tumor in a patient with high-risk polycythemia vera: illustrative case

Abstract

Background: Here the authors present the case of a 43-year-old male with a history of T-cell lymphoma, which was treated with azacitidine plus cyclophosphamide, doxorubicin, vincristine, and prednisone and autologous hematopoietic cell transplant, and high-risk polycythemia vera (PCV) presenting with severe lower-back pain radiating to the bilateral legs with associated lower-extremity weakness and splenomegaly.

Observations: T2-weighted magnetic resonance imaging revealed multilevel epidural lesions involving T1-10 and S1-2. Because of severe spinal canal stenosis, the patient underwent surgical decompression of T5-7, with immediate postoperative alleviation of the lower-extremity pain and complete resolution of the lower-leg weakness. Biopsy results revealed extramedullary hematopoiesis (EMH) mimicking a spinal epidural tumor. EMH is radiosensitive and displays a rapid response to low dosages, so the patient was further treated with palliative radiation therapy for residual tumors and symptom alleviation, as well as hydroxyurea and corticosteroids as indicated for cytoreduction.

Lessons: EMH associated with PCV or myeloproliferative conditions occurring within the spine is a rare phenomenon without a standard treatment approach. https://thejns.org/doi/10.3171/CASE23659.

Keywords: epidural tumor; extramedullary hematopoiesis; polycythemia vera; spine.

FIG. 1.

Sagittal (left) and axial (right) T2-weighted MRI at T6 revealed significant mass effect secondary to a dorsal epidural lesion extending from T1 to T10, causing severe central canal stenosis, particularly from T5 to T7.