Epidural Spinal Cord Compression due to Extramedullary Hematopoiesis: Systematic Review of the Literature with an Illustrative Case

BACKGROUND: Epidural extramedullary hematopoiesis EMH) is a rare, underreported phenomenon in which hematopoiesis occurring outside of the medullary environment can cause spinal cord compression. In this systematic review, we evaluate clinical characteristics and evidence-based guidelines for clinical management of EMH and present an illustrative case. METHODS: A comprehensive search of the PubMed, Scopus, and Embase databases was conducted. Clinical and radiographic data on the patient characteristics, diagnoses, histories, treatment paradigms, and outcomes were extracted from eligible studies. RESULTS: A total of 50 articles, including 54 patients (mean age at presentation, 37.9 years, 83.3% male) met inclusion criteria. Among patients, exam revealed motor/sensory deficit, back pain, bladder and bowel dysfunction, and gait disturbance due to masses impacting the thoracic (87.0%), lumbar (25.9%), sacral (16.7%), and cervical (5.6%) spine, often with multifocal EMH (24.1%). Fifty-two patients received treatment consisting of surgical resection, low-dose radiotherapy, or medical treatment such as transfusion (62%), hydroxyurea (24%), and steroids (24%). Primary treatment in 59.3% of patients was multimodal, with surgery (with/without adjunctive therapy) and early treatment (<1 month from symptom onset) correlating with a reduction in poor outcomes. CONCLUSIONS: Epidural EMH is a pathology with limited reporting; this systematic review is the most comprehensive to date. Although available case series data were heterogeneous, our analysis suggested that multimodal treatment with surgical intervention was beneficial. Given the young patient population, we recommend prompt surgical management via decompression of the spine because of the associated low risk of complications and recurrence, and better neurological recovery.