How do I diagnose Extramedullary Hematopoiesis

  • Rita Carvalho
  • Manuela Mafra


Extramedullary hematopoiesis occurs in bone marrow disorders and is most commonly seen in thalassemia and myelofibrosis. We present a case of a 58 year-old male, with a history of thalassemia, which presented with a para-vertebral mass composed of hematopoietic tissue. When considering the differential diagnosis, a primary concern was an extramedullary proliferation of neoplastic hematopoietic elements, like extramedullary myeloid sarcoma. Neoplastic extramedullary proliferations can consist of triline age marrow elements and closely mimic the appearance of benign extramedullary hematopoiesis. The morphologic appearance may be a diagnostic clue, but cannot be completely relied upon.


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Author Biography

Rita Carvalho

Pathology Resident - Central Lisbon Hospital Center

Lisbon - Portugal


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How to Cite
CARVALHO, Rita; MAFRA, Manuela. How do I diagnose Extramedullary Hematopoiesis. Diagnostic Pathology, [S.l.], v. 2, n. 1, apr. 2016. ISSN 2364-4893. Available at: <>. Date accessed: 04 mar. 2024. doi:
How do I diagnose


Extramedullary hematopoiesis; Extramedullary myeloid sarcoma; : Posterior mediastinum, para-vertebral mass; CD34, CD117, TdT

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