Tumors of the hematopoietic and lymphoid tissues | |
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Micrograph of a plasmacytoma, a hematological malignancy | |
Classification and external resources | |
Specialty | oncology |
ICD-10 | C81-C96 |
ICD-9-CM | 200-209 |
ICD-O | 9590-9999 |
MeSH | D019337 |
Tumors of the hematopoietic and lymphoid tissues or haematopoietic and lymphoid malignancies are tumors that affect the blood, bone marrow, lymph, and lymphatic system. As those elements are all intimately connected through both the circulatory system and the immune system, a disease affecting one will often affect the others as well, making myeloproliferation and lymphoproliferation (and thus the leukemias and the lymphomas) closely related and often overlapping problems.
While uncommon in solid tumors, chromosomal translocations are a common cause of these diseases. This commonly leads to a different approach in diagnosis and treatment of haematological malignancies.
Haematological malignancies are malignant neoplasms ("cancer"), and they are generally treated by specialists in hematology and/or oncology. In some centers "Haematology/oncology" is a single subspecialty of internal medicine while in others they are considered separate divisions (there are also surgical and radiation oncologists). Not all haematological disorders are malignant ("cancerous"); these other blood conditions may also be managed by a hematologist.
Hematological malignancies may derive from either of the two major blood cell lineages: myeloid and lymphoid cell lines. The myeloid cell line normally produces granulocytes, erythrocytes, thrombocytes, macrophages and mast cells; the lymphoid cell line produces B, T, NK and plasma cells. Lymphomas, lymphocytic leukemias, and myeloma are from the lymphoid line, while acute and chronic myelogenous leukemia, myelodysplastic syndromes and myeloproliferative diseases are myeloid in origin.