title: Intracranial extramedullary hematopoiesis: a rare cause of headaches.
abstract: BACKGROUND
  Ectopic bone marrow production, known as extramedullary hematopoiesis, may result in symptoms due to compression on normal structures. We present the multimodality imaging findings and subsequent management of a rare case of symptomatic extramedullary hematopoiesis within the calvarium.
  
  
  METHODS
  Case report.
  
  
  RESULTS
  A 54-year-old male with a history of myelofibrosis and no previous diagnosis of a headache disorder presented to the emergency department with worsening severe bilateral headaches. A nonenhanced CT of the brain was performed and diffuse extra-axial nodular hyperdensities were visualized. MRI of the brain demonstrated diffuse extra-axial avidly enhancing nodular masses, dural thickening and marked susceptibility. No paravertebral masses, typical for extramedullary hematopoiesis, were present in the chest or abdomen. Although the clinical team considered a biopsy to confirm the diagnosis, we suggested a noninvasive confirmatory test. The subsequent Tc99m sulfur colloid scan corroborated the diagnosis. The patient was then referred to radiation oncology for treatment.
  
  
  CONCLUSIONS
  In summary, extramedullary hematopoiesis is a hematologic compensatory disorder that rarely occurs within the CNS and may cause neurological compromise due to compression on underlying structures. The diagnosis can be made with noninvasive imaging and treated with low dose radiation therapy.
authors.affiliation: Department of Radiology, Jackson Memorial Hospital, Miami, FL.
authors.forename: Adam
authors.initials: A
authors.lastname: Singer
authors.forename: Robert
authors.initials: R
authors.lastname: Quencer
mesh_terms: D001927:Brain Diseases / Q000175:diagnosis* / Q000209:etiology*; D006261:Headache / Q000175:diagnosis* / Q000209:etiology*; D006411:Hematopoiesis, Extramedullary; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: CT; Extramedullary hemato-poiesis; MRI; intracranial; sulfur colloid; susceptibility