Bone marrow nonneoplastic

Alterations in cellularity


Last author update: 1 March 2013
Last staff update: 8 August 2022

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PubMed Search: Bone marrow amegakaryocytic thrombocytopenia

Dragos C. Luca, M.D.
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Cite this page: Luca DC. Amegakaryocytosis. website. Accessed June 3rd, 2023.
Amegakaryocytic thrombocytopenia
Definition / general
  • Also called CAMT (congenital amegakaryocytic thrombocytopenia)
  • Extremely rare, usually diagnosed in early childhood (Pediatr Blood Cancer 2011;57:199, Hematol Oncol Clin North Am 2009;23:321)
  • Initially thought to have variable inheritance (autosomal recessive or X linked) but X linked forms now reinterpreted as mild or attenuated forms of Wiskott-Aldrich syndrome


Clinical features and diagnosis
  • Isolated nonimmune thrombocytopenia with decreased marrow megakaryocytes and high serum TPO levels
  • Red cell macrocytosis with normal hemoglobin level
  • Bone marrow initially normocellular
  • Mucocutaneous or GI bleeding, variable physical abnormalities (Br J Haematol 2005;131:636)

Case reports

Treatment and prognosis
  • Stem cell transplantation
  • 50% evolve to aplastic anemia (at mean age 3.5 years); may evolve to myelodysplastic syndrome or leukemia

Microscopic (histologic) images

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Bone marrow aspiration and trephine biopsy

Cytology images

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Bone marrow failure in child

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