Acquired Amegakaryocytic Thrombocytopenia

**Semantic type:** Disease or Syndrome

**Definition:** A rare bone marrow disorder characterized by a marked decrease or complete absence of megakaryocytes with preservation of all other hematopoietic cell lineages. Causes include toxins, viruses, drugs, and humoral and cell-mediated suppression of megakaryocytopoeisis. It usually presents with bleeding, severe thrombocytopenia, and absence of splenomegaly. It is often misdiagnosed as immune thrombocytopenic purpura (ITP).

**Synonyms:** - AAMT - AAT - AATP - Acquired Amegakaryocytic Thrombocytopenic Purpura