Hematopathology - Diseases of Hematopoietic Cells

Diseases of Hematopoietic Cells

Diseases of the hematopoietic system are myriad and include hereditary and congenital disorders as well as acquired disorders. Hereditary and congenital disorders include, in part, bone marrow failure syndromes and primary deficiency syndromes. Acquired disorders may be related to nutritional deficiencies (such as iron, folate, and B12 deficient anemias), infectious processes or neoplastic disorders (cancers). Diagnostic criteria and classification guidelines for the neoplastic diseases are codified in the WHO Classification of Tumours of the Hematopoietic and Lymphoid Tissue, most recently revised in 2008. The neoplastic diseases of hematopoietic cells fall into two broad categories, myeloid neoplasms and lymphoid neoplasms. Histiocytic and dendritic cell neoplasms are considered separately.

– Myeloid Neoplasms:

Myeloproliferative neoplasms Myeloid and lymphoid disorders with eosinophilia Myeloproliferative/myelodysplastic neoplasms Myelodysplastic syndromes Acute myeloid leukemia and related precursor neoplasms Acute leukemia of ambiguous lineage

– Lymphoid Neoplasms

Precursor lymphoid neoplasms Mature B-cell neoplasms Mature T-cell neoplasms Hodgkin lymphoma Immunodeficiency associated lymphoproliferative disorders

– Histiocytic and Dendritic Cell Neoplasms

Each category contains several recognized diagnostic entities resulting in nearly 100 different types of hematopoietic cancer, each with defining morphology, pathobiology, treatment, and/or prognostic features. Correct classification, as well as identification of additional factors that may influence prognosis or response to chemotherapy, is essential to allow optimal treatment by the hematologist/oncologist. The hematopathologist is also responsible for additional studies performed after initiation of therapy to monitor for continued remission or disease relapse.