Section Editor: David Li MD
May 25, 2026
Blood is made up of cells that carry oxygen, fight infection, and help the blood to clot. These cells are produced in the bone marrow, the soft tissue inside the bones. Conditions of the blood and bone marrow are diagnosed using blood samples and bone marrow samples, which a pathologist examines under a microscope and with other laboratory tests. The findings are described in your pathology report.
This page brings together our guides to conditions of the blood and bone marrow. The articles are grouped by type to help you find the one that matches your diagnosis. Select any article below to learn more.
Cancers of the blood and bone marrow
These diagnoses are cancers that start in the blood-forming cells of the bone marrow or in related cells of the immune system. They include the leukemias, lymphomas, myeloma, and related conditions. The articles explain how each type is diagnosed and what the details in your pathology report mean.
Acute lymphoblastic leukemia, or ALL, is a fast-growing cancer of immature white blood cells called lymphoblasts. It is the most common cancer in children but can also affect adults. This article gives an overview of the diagnosis and its types.
You may find this helpful if your report mentions acute lymphoblastic leukemia or ALL.
B-lymphoblastic leukemia, or B-ALL, is a type of acute lymphoblastic leukemia that develops from immature B cells. This article explains what this diagnosis means and what your pathology report describes.
You may find this helpful if your report mentions B-lymphoblastic leukemia or B-ALL.
B-lymphoblastic lymphoma, or B-LBL, is closely related to B-lymphoblastic leukemia. It develops from the same immature B cells but forms a mass rather than mainly involving the blood and bone marrow. This article explains what this diagnosis means.
You may find this helpful if your report mentions B-lymphoblastic lymphoma or B-LBL.
T-cell acute lymphoblastic leukemia
T-cell acute lymphoblastic leukemia, or T-ALL, is a type of acute lymphoblastic leukemia that develops from immature T cells. This article explains what this diagnosis means, including the closely related T-lymphoblastic lymphoma.
You may find this helpful if your report mentions T-cell acute lymphoblastic leukemia, T-ALL, or T-lymphoblastic lymphoma.
Acute myeloid leukemia, or AML, is a fast-growing cancer of immature blood-forming cells in the bone marrow. This article explains how it is diagnosed and what the details in your pathology report mean.
You may find this helpful if your report mentions acute myeloid leukemia or AML.
Chronic lymphocytic leukemia, or CLL, is a slow-growing cancer of mature B cells. This article explains how it is diagnosed and what the details in your pathology report mean.
You may find this helpful if your report mentions chronic lymphocytic leukemia or CLL.
Hairy cell leukemia is an uncommon, slow-growing cancer of mature B cells. It is named for the fine, hair-like edges of the cells seen under the microscope. This article explains what this diagnosis means.
You may find this helpful if your report mentions hairy cell leukemia.
Adult T cell leukemia is an uncommon cancer of mature T cells that is linked to a virus called HTLV-1. This article explains what this diagnosis means and what your pathology report describes.
You may find this helpful if your report mentions adult T cell leukemia or lymphoma.
Lymphoplasmacytic lymphoma, or LPL, is a slow-growing cancer of B cells that often produces a protein called IgM. This article explains what this diagnosis means.
You may find this helpful if your report mentions lymphoplasmacytic lymphoma or LPL, or Waldenstrom macroglobulinemia.
Chronic myeloid leukemia, or CML, is a slow-growing cancer of blood-forming cells, caused by a specific genetic change in the bone marrow. This article explains what this diagnosis means.
You may find this helpful if your report mentions chronic myeloid leukemia or CML.
Polycythemia vera is a slow-growing blood cancer in which the bone marrow makes too many red blood cells. This article explains what this diagnosis means.
You may find this helpful if your report mentions polycythemia vera.
Essential thrombocythemia is a slow-growing blood cancer in which the bone marrow makes too many platelets, the cells that help blood to clot. This article explains what this diagnosis means.
You may find this helpful if your report mentions essential thrombocythemia.
Primary myelofibrosis is a slow-growing blood cancer in which scar tissue builds up in the bone marrow. This article explains what this diagnosis means.
You may find this helpful if your report mentions primary myelofibrosis.
Myelodysplastic syndromes, or MDS, are a group of bone marrow cancers in which blood-forming cells do not develop normally. This article explains what this diagnosis means and what your pathology report describes.
You may find this helpful if your report mentions a myelodysplastic syndrome or MDS.
Multiple myeloma is a cancer of plasma cells, a type of immune cell found in the bone marrow. This article explains how it is diagnosed and what the details in your pathology report mean.
You may find this helpful if your report mentions multiple myeloma or plasma cell myeloma.
Langerhans cell histiocytosis is an uncommon condition in which the body makes too many of a specific immune cell. It can affect one part of the body or several. This article explains what this diagnosis means.
You may find this helpful if your report mentions Langerhans cell histiocytosis.
Precursor conditions
This diagnosis is a noncancerous condition that can, in some people, develop into a blood cancer over time. It is not cancer, and many people with it never develop cancer, but it is followed with regular testing. The article explains what this diagnosis means.
Monoclonal gammopathy of undetermined significance
Monoclonal gammopathy of undetermined significance, or MGUS, is a noncancerous condition in which plasma cells make a small amount of an abnormal protein. In a small number of people it can develop into multiple myeloma over time. This article explains what this diagnosis means.
You may find this helpful if your report mentions monoclonal gammopathy of undetermined significance or MGUS.
Noncancerous blood conditions
These diagnoses are noncancerous conditions of the blood. They are not cancer. Most are types of anemia, which means a low number of red blood cells or a low level of the oxygen-carrying protein they contain. The articles explain what each diagnosis means.
Iron-deficiency anemia is a common, noncancerous condition in which the body does not have enough iron to make healthy red blood cells. This article explains what this diagnosis means.
You may find this helpful if your report mentions iron-deficiency anemia.
Anemia of chronic disease is a noncancerous type of anemia that develops alongside a long-lasting illness, such as an infection or an inflammatory condition. This article explains what this diagnosis means.
You may find this helpful if your report mentions anemia of chronic disease.
Megaloblastic anemia is a noncancerous type of anemia caused by a shortage of vitamin B12 or folate, which the body needs to make healthy red blood cells. This article explains what this diagnosis means.
You may find this helpful if your report mentions megaloblastic anemia.
Hemolytic anemia is a noncancerous type of anemia in which red blood cells are destroyed faster than the body can replace them. This article explains what this diagnosis means.
You may find this helpful if your report mentions hemolytic anemia.
Normocytic normochromic anemia
Normocytic normochromic anemia is a type of anemia in which the red blood cells are normal in size and color but too few in number. This article explains what this diagnosis means and what can cause it.
You may find this helpful if your report mentions normocytic normochromic anemia.
Thrombotic microangiopathy is a noncancerous but serious condition in which small blood clots form in tiny blood vessels throughout the body. This article explains what this diagnosis means and what a pathologist looks for.
You may find this helpful if your report mentions thrombotic microangiopathy.
We are proud to partner with:
