Acquired amegakaryocytic thrombocytopenia: Three case reports and a literature review

Abstract

Acquired amegakaryocytic thrombocytopenia (AAT) is a rare disease characterized by thrombocytopenia due to selective reduction/absence of bone marrow (BM) megakaryocytes. In the BM culture isolated reduction of colony-forming units-megakaryocyte (CFU-Mk) may occur. BM aspirates and trephine biopsies were obtained from all patients and processed by routine methods. In vitro BM culture and cytogenetic analysis was performed in one patient. This article presents three patients with manifested signs of hemorrhagic syndrome due to severe thrombocytopenia caused by an absence/significant reduction of BM megakaryocytes. Existence of systemic or any other disease was excluded in all patients. BM culture of the second patient showed reduction of all hematopoietic progenitors. In the subsequent course of the disease in this patient, signs of dysplastic erythrocytic series and megakaryocytes were also noted, although there were no positive proofs of evolution into myelodysplastic syndrome. AAT is a disease of hematopoietic stem cells manifesting in a certain period as amegakaryocytic thrombocytopenia which subsequently may progress into aplastic anemia or myelodysplastic syndrome. Patients were treated with corticosteroids, lithium carbonate, androgens, vincristine, immunoglobulins, folic acid, platelet and erythrocyte transfusions along with plasma substitution. The first patient reacted positively to the therapy. In two other patients a minimal, short-term therapeutic effect was achieved, followed by improvement of hemorrhagic syndrome and an insignificant increase in platelet count. In one patient the treatment was stopped after 4 months and the other died of bleeding after 4 months. AAT is a rare disease with unpredictable course. This is a case report of three patients with AAT and different therapeutic effects.