Tumors of the hematopoietic and lymphoid tissues

A type of tumor affecting blood and lymphoid tissues

Tumors of the hematopoietic and lymphoid tissues are a diverse group of neoplasms that affect the blood, bone marrow, lymph, and lymphatic system. These tumors are generally classified into two main categories: leukemias and lymphomas, although other types exist.

Classification

Tumors of the hematopoietic and lymphoid tissues are classified based on the type of cell from which they originate. The World Health Organization (WHO) classification system is commonly used and includes:

• Leukemias: These are cancers of the blood or bone marrow characterized by an abnormal increase of white blood cells. They are further divided into acute and chronic forms, and by the type of white blood cell affected (e.g., acute lymphoblastic leukemia, chronic myeloid leukemia).

• Lymphomas: These are cancers that originate in the lymphatic system. The two main types are Hodgkin lymphoma and non-Hodgkin lymphoma.

• Plasma cell neoplasms: These include multiple myeloma and plasmacytoma, which are characterized by the proliferation of plasma cells.

• Myelodysplastic syndromes: These are a group of disorders caused by poorly formed or dysfunctional blood cells.

• Myeloproliferative neoplasms: These are diseases of the bone marrow in which excess cells are produced.

Pathophysiology

The pathophysiology of these tumors involves genetic mutations that lead to uncontrolled cell growth. These mutations can be inherited or acquired. Environmental factors, such as exposure to radiation or certain chemicals, can also contribute to the development of these tumors.

Diagnosis

Diagnosis typically involves a combination of physical examination, blood tests, bone marrow biopsy, and imaging studies. Specific tests, such as flow cytometry and cytogenetic analysis, are used to identify the type of tumor and its characteristics.

Treatment

Treatment varies depending on the type and stage of the tumor. Common treatments include chemotherapy, radiation therapy, targeted therapy, and stem cell transplantation. The choice of treatment is influenced by the patient's age, overall health, and specific characteristics of the tumor.

Prognosis

The prognosis for patients with tumors of the hematopoietic and lymphoid tissues varies widely. Factors influencing prognosis include the type of tumor, stage at diagnosis, and response to treatment. Advances in treatment have improved outcomes for many patients.

Related pages

• Leukemia
• Lymphoma
• Multiple myeloma
• Hematology

References

• Swerdlow, S. H., Campo, E., Harris, N. L., Jaffe, E. S., Pileri, S. A., Stein, H., ... & Vardiman, J. W. (Eds.). (2017). WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. International Agency for Research on Cancer.
• American Cancer Society. (2023). Understanding Blood and Lymphatic System Cancers. Retrieved from [1]

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Micrograph of a plasmacytoma, a type of plasma cell neoplasm.

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