Types of Blood Disorders and Cancers
Hematologist-oncologists treat blood cancers such as leukemia as well as non-malignant blood disorders.
Leukemia is cancer of the blood cells — usually the white blood cells. There are four main types of leukemia, which can be further divided into subtypes.
The first step for the hematologist-oncologist is to determine if the cancer is:
- Lymphocytic or myelogenous leukemia, which can occur in either the lymphoid or myeloid white blood cells.
- Lymphocytic leukemia, when the cancer develops in the lymphocytes (lymphoid cells).
- Myelogenous leukemia, when the cancer develops in the myeloid cells, usually the granulocytes or monocytes.
- Acute or chronic leukemia
- In the acute form, the new or immature cancer cells, called blasts, remain very immature and cannot function properly. The blasts multiply rapidly, and the disease progresses quickly.
- In the chronic form, the affected cells are more mature and often are able to perform some of their functions. The cells grow more slowly, and the number increases less quickly, so the disease progresses gradually.
Myelodysplastic syndromes are blood-related conditions that involve ineffective production (dysplasia) of the myeloid class of blood cells. These cells develop into red blood cells, white blood cells (other than lymphocytes), or platelets. Subtypes of myelodysplastic syndromes are distinguished by what kind of blood cell is affected. In time, some patients who have a myelodysplastic syndrome may develop leukemia.
Myeloproliferative disorders are rare illnesses that cause blood cells generated in the bone marrow —red blood cells, white blood cells, and platelets — to grow and develop abnormally. In some cases, the disease progresses slowly and requires minimal treatment. In some patients, it develops into acute myeloid leukemia (AML).
Bone Marrow Failure Syndromes
Bone marrow is the soft, spongy tissue inside bones where blood cells are produced. Bone marrow failure syndromes occur when the bone marrow fails to produce enough new blood cells.
Hodgkin Lymphoma (Hodgkin Disease)
Hodgkin lymphoma is a malignant, progressive disease of unknown cause, marked by enlargement of the lymph nodes, spleen, and liver. The body has hundreds of lymph nodes that filter harmful substances from lymph fluid. The lymph nodes have immune cells that can help fight infection. A large number of Reed-Sternberg cells — large, abnormal lymphocytes (a kind of white blood cell) that may contain more than one nucleus — is found in the blood of Hodgkin lymphoma patients. As the disease advances, the number increases.
Non-Hodgkin lymphoma refers to malignant lymphomas characterized by the absence of Reed-Sternberg cells, which are large, abnormal lymphocytes that may contain more than one nucleus. Symptoms of non-Hodgkin lymphoma are similar to those of Hodgkin disease.
Multiple myeloma is a cancer of plasma cells. These cells are primarily located in the bone marrow. Multiple myeloma can cause bone fractures, low red blood cell counts, and kidney failure. It is most often identified through the discovery of excess protein in the blood.