Hematology Ch 19 Bone Marrow Failure Study Resource

Pancytopenia

A concurrent reduction in all three major peripheral blood cell lines (erythrocytes, leukocytes, and platelets), clinically presenting with fatigue, recurrent bacterial infections, and mucocutaneous bleeding.

Acquired aplastic anemia

A disorder characterized by pancytopenia and a markedly hypocellular bone marrow replaced predominantly by fat, caused by stem cell depletion in the absence of an inherited genetic condition.

Primary pathophysiologic mechanism of acquired aplastic anemia

Autoimmune destruction of hematopoietic stem and progenitor cells mediated by cytotoxic T lymphocytes.

Very severe aplastic anemia criteria

Fulfillment of severe aplastic anemia criteria alongside an absolute neutrophil count (ANC) strictly below $0.2 \times 10^9/\text{L}$.

Characteristic peripheral blood findings in severe aplastic anemia

Pancytopenia, severe reticulocytopenia, and mild macrocytosis, with an absence of circulating blasts or immature myeloid precursors.

Optimal curative treatment for young patients with severe aplastic anemia and an HLA-matched sibling

Allogeneic hematopoietic stem cell transplantation.

Fanconi anemia

An inherited bone marrow failure syndrome caused by defective DNA repair, characterized by chromosomal fragility upon diepoxybutane (DEB) testing, short stature, radial or thumb dysplasia, and skin hyperpigmentation.

Dyskeratosis congenita

An inherited disorder caused by mutations affecting telomere maintenance complexes, leading to accelerated telomere shortening and a classic clinical triad of reticular skin pigmentation, nail dystrophy, and oral leukoplakia.

Shwachman-Diamond syndrome

An inherited bone marrow failure syndrome characterized by neutropenia, recurrent infections, exocrine pancreatic insufficiency, and metaphyseal chondrodysplasia.

Diamond-Blackfan anemia

A congenital pure red cell aplasia presenting in early infancy with severe anemia, profound reticulocytopenia, and normal white blood cell and platelet counts.

Transient erythroblastopenia of childhood (TEC)

A self-limiting, acquired suppression of erythropoiesis typically occurring in young children following a viral illness, characterized by severe anemia with reticulocytopenia while sparing granulocytes and platelets.

Congenital dyserythropoietic anemia (CDA)

A group of rare inherited anemias marked by ineffective erythropoiesis, reticulocytopenia, secondary hemosiderosis, and binucleated or multinucleated erythroid precursors in the bone marrow.

Myelophthisic anemia

Bone marrow failure resulting from space-occupying lesions (e.g., metastatic tumor or fibrosis) displacing normal hematopoietic tissue, typically producing dacrocytes (teardrop cells) and a leukoerythroblastic blood picture.

Primary mechanism of anemia in chronic kidney disease

Impaired synthesis of erythropoietin (EPO) by damaged peritubular interstitial cells in the renal cortex.

Marrow cellularity distinction between aplastic anemia and acute leukemia

Aplastic marrow is markedly hypocellular and replaced by adipose tissue, whereas acute leukemia demonstrates a hypercellular marrow infiltrated by malignant blast cells.