Aplastic Anemia (Hypoplastic Anemia) By Gloria F Gerber, MD, Johns Hopkins School of Medicine, Division of Hematology Reviewed / Revised Jun 2023 View Patient Education Etiology Symptoms and Signs Diagnosis Treatment Key Points Topic Resources Petechiae in Immune Thrombocytope... Ecchymoses in Immune Thrombocytop.. Aplastic anemia is a disorder of the hematopoietic stem cell that results in a loss of blood cell precursors, hypoplasia or aplasia of bone marrow, and cytopenias in two or more cell lines (red blood cells, white blood cells, and / or platelets).