Intracranial Extramedullary Hematopoiesis

HomeRadioGraphicsVol. 44, No. 2 PreviousNext Cases from the Cooky JarFree AccessIntracranial Extramedullary HematopoiesisDhairya A. Lakhani , Julia Niemierko, George K. Vilanilam, Ciléin Kearns, Jeffrey S. CarpenterDhairya A. Lakhani , Julia Niemierko, George K. Vilanilam, Ciléin Kearns, Jeffrey S. CarpenterAuthor AffiliationsFrom the Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, 600 N Wolfe St, Phipps B-100, Baltimore, MD 21287 (D.A.L.); Department of Radiology, Medical University Hospital of Gdansk, Gdansk, Poland (J.N.); Department of Radiology, University of Arkansas for Medical Sciences, Little Rock, Ark (G.K.V.); Artibiotics, Wellington, New Zealand, and Department of Radiology, Wellington Regional Hospital, Te Whatu Ora, Wellington, New Zealand (C.K.); and Department of Neuroradiology, West Virginia University, Morgantown, WV (J.S.C.).Address correspondence to D.A.L. (email: [email protected]).Dhairya A. Lakhani Julia NiemierkoGeorge K. VilanilamCiléin KearnsJeffrey S. CarpenterPublished Online:Jan 18 2024https://doi.org/10.1148/rg.230218MoreSectionsPDF ToolsAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookXLinked In Extramedullary hematopoiesis (EMH) refers to the production of blood cells outside the bone marrow. EMH occurs when bone marrow hematopoiesis is ineffective or insufficient, leading to stem and progenitor cells migrating to alternative sites that become substitute hematopoietic organs (1) (Fig 1). EMH is almost always asymptomatic but can cause symptoms related to mass effect (2). On CT images, these typically manifest as multiple extra-axial hyperattenuating foci along the cerebral convexities, falx cerebri, or tentorium cerebelli, mimicking tumors (meningiomas) and intracranial hemorrhage (most frequently subdural hematoma) (Fig 2) (3,4). MRI demonstrates intermediate T1-weighted and heterogeneous T2-weighted signal intensity, except after transfusion, when iron deposition results in decreased signal intensity with both sequences (Fig 3). Technetium 99m (99mTc) sulfur colloid scintigraphy helps confirm the presence of bone marrow elements within masses, which is especially beneficial in hard-to-biopsy cases (3)(Fig 4).Figure 1. Medical illustration depicts the pathogenesis of extramedullary hematopoiesis. (Reprinted, with permission, from Ciléin Kearns, Artibiotics, Copyright © 2023.).Figure 1.Download as PowerPointFigure 2. Extramedullary hematopoiesis in a 49-year-old woman with osteopetrosis. Axial CT image of the brain displays a thin hyperattenuating collection (arrows) along the left cerebral convexity.Figure 2.Download as PowerPointFigure 3. Extramedullary hematopoiesis in a 49-year-old woman with osteopetrosis. Axial brain MR precontrast T1-weighted (A), T2-weighted (B), and T1-weighted postcontrast (C) images show extra-axial collections bilaterally along the cerebral convexities (left greater than right) (arrows). These collections demonstrate intermediate T1 signal intensity (A), heterogeneous T2 signal intensity (B), and heterogeneous contrast enhancement (C), suggesting extramedullary hematopoiesis. Note the absence of the normal T1 fat signal intensity in the skull bone marrow, which is consistent with the clinical history of osteopetrosis.Figure 3.Download as PowerPointFigure 4. Axial 99mTc sulfur colloid scintigraphic image shows radiotracer uptake in the bilateral extra-axial deposits (arrows), confirming the diagnosis of intracranial extramedullary hematopoiesis.Figure 4.Download as PowerPointManagement in symptomatic cases involves either treatment of the underlying cause or blood transfusions when other treatment is not possible. In refractory cases, radiation therapy, surgery, and hydroxyurea and steroid therapy can be helpful (5,6).Disclosures of conflicts of interest.—G.K.V. Editorial board member of RadioGraphics. C.K. Editorial board member of RadioGraphics. All other authors have disclosed no relevant relationships.References1. Mende N, Laurenti E. Hematopoietic stem and progenitor cells outside the bone marrow: where, when, and why. Exp Hematol 2021;104:9–16. Crossref, Medline, Google Scholar2. Georgiades CS, Neyman EG, Francis IR, Sneider MB, Fishman EK. Typical and atypical presentations of extramedullary hemopoiesis. AJR Am J Roentgenol 2002;179(5):1239–1243. Crossref, Medline, Google Scholar3. Palma JA, Dominguez PD, Riverol M. Intracranial extramedullary hematopoiesis associated with multiple myeloma. Neurology 2013;80(17):1620. Crossref, Medline, Google Scholar4. Tun K, Kaptanoglu E, Celikmez RC, Gurcan O, Turkoglu OF, Kutluay L. Meningeal extramedullary haematopoiesis mimicking subdural hematoma. J Clin Neurosci 2008;15(2):208–210. Crossref, Medline, Google Scholar5. Roberts AS, Shetty AS, Mellnick VM, Pickhardt PJ, Bhalla S, Menias CO. Extramedullary haematopoiesis: radiological imaging features. Clin Radiol 2016;71(9):807–814. Crossref, Medline, Google Scholar6. Mattei TA, Higgins M, Joseph F, Mendel E. Ectopic extramedullary hematopoiesis: evaluation and treatment of a rare and benign paraspinal/epidural tumor. J Neurosurg Spine 2013;18(3):236–242. Crossref, Medline, Google ScholarArticle HistoryReceived: Sept 21 2023Accepted: Oct 5 2023Published online: Jan 18 2024 FiguresReferencesRelatedDetailsRecommended Articles Imaging Spectrum of Calvarial AbnormalitiesRadioGraphics2021Volume: 41Issue: 4pp. 1144-1163Craniofacial Manifestations of Systemic Disorders: CT and MR Imaging Findings and Imaging ApproachRadioGraphics2018Volume: 38Issue: 3pp. 890-911Pediatric Central Nervous System Imaging of Nonaccidental Trauma: Beyond Subdural HematomasRadioGraphics2018Volume: 39Issue: 1pp. 213-228Traumatic Brain Injury: Imaging Patterns and ComplicationsRadioGraphics2019Volume: 39Issue: 6pp. 1571-1595Systematic Approach to Pediatric MacrocephalyRadioGraphics2023Volume: 43Issue: 5See More RSNA Education Exhibits When Sugar Looks Like Salt: Pitfalls That Could Lead To The Incorrect Diagnosis Of Child AbuseDigital Posters2021Artificial intelligence (AI) Based Decision Support Software for the Detection of Intracranial Hemorrhage—Experience of Two Years of Use and ConsiderationsDigital Posters2020A Radiologist's Lexicon For Reporting In Child AbuseDigital Posters2021 RSNA Case Collection Spontaneous Epidural Hematoma RSNA Case Collection2021Vertex epidural hematoma RSNA Case Collection2021Clival Chordoma RSNA Case Collection2020 Vol. 44, No. 2 Metrics Altmetric Score PDF download