Leukemia associated with hyperplasia and overactivity of the lymphoid tissue; there are increased numbers of circulating malignant lymphocytes and lymphoblasts.

Lymphoid leukemias are a group of leukemias affecting circulating lymphocytes, a type of white blood cell. The lymphocytic leukemias are closely related to lymphomas of the lymphocytes, to the point that some of them are unitary disease entities that can be called by either name (for example, adult T-cell leukemia/lymphoma)...