Diagnosis

An accurate diagnosis is one of the most important aspects of a person’s care. Obtaining a precise diagnosis will help the doctor

  • Determine the MDS subtype 
  • Estimate how the disease will progress
  • Determine the most appropriate treatment

Since MDS can be a difficult disease to diagnose, you may want to get a second medical opinion by an experienced hematopathologist before you begin treatment.

Diagnostic Criteria

The diagnosis of MDS is based on:

  • At least one cytopenia (low blood cell count) in red blood cell, white blood cell and/or platelet counts
  • Dysplasia (cells that have an abnormal size or shape) in at least 10 percent or more of red blood cells, white blood cells or platelets on the blood smear or bone marrow examination
  • Less than 20 percent blasts (immature blood cells) in the blood and bone marrow
  • Specific MDS-associated cytogenetic (chromosome) abnormalities

In healthy people, there are usually no blast cells in the blood, and blast cells should make up less than 5 percent of all bone marrow cells. In MDS patients, blast cells may make up to 20 percent of cells in the bone marrow. A blast count of 20 percent or higher is considered acute myeloid leukemia (AML).

Complete Blood Cell Count with Differential. A doctor will order a complete blood count (CBC) with differential to measure the number of red cells, white cells and platelets in your blood. These measurements indicate the degree to which the MDS cells in the marrow are affecting normal blood cell development. Patients with MDS often have low numbers of one or more types of blood cells. The CBC should include a "differential." This measures the different types of white blood cells in the sample. 

Reticulocyte Count. Reticulocytes are precursor (immature) cells that develop into mature red blood cells. The reticulocyte count measures the number of reticulocytes in the circulating blood. It can show how quickly these cells are being made and released by the bone marrow and whether the bone marrow is functioning properly. When a person has anemia, the normal response is for the bone marrow to make more reticulocytes. A low reticulocyte count indicates that the bone marrow is not working well.

Peripheral Blood Smear. A peripheral blood smear is a test in which a hematopathologist examines a drop of blood under a microscope to identify unusual changes in the number, size, shape, appearance and maturity of various blood cells. In myelodysplastic syndromes, blood cells have an abnormal shape or size (dysplasia). The hematopathologist will also check a peripheral blood smear for the presence of blast cells. Blast cells are normally found in the bone marrow, but they are not typically found in the blood of healthy individuals. In some cases of MDS, a small number of blast cells can be found in the blood.

Serum Erythropoietin (EPO). Erythropoietin (EPO) is a substance made in the kidneys. EPO stimulates the bone marrow to produce more red blood cells. Measuring the amount of EPO in the blood can help determine the cause of anemia. A low EPO level can cause anemia and may be a sign of a health problem other than MDS. A low EPO level can also worsen anemia in a person with MDS. Most patients with MDS-related anemia have relatively low serum levels of EPO.

Lactate dehydrogenase (LDH). This test measures the level of lactate dehydrogenase (LDH) in the blood. LDH is a protein found in most cells. When a cell is damaged, LDH is released into the bloodstream. High levels of LDH in the blood may be caused by cancer and may also be a sign that the cancer is widespread. 

Bone Marrow Tests: Aspiration and Biopsy. These tests are used to confirm MDS. They are usually performed at the same time in a doctor's office or a hospital. After the samples are taken, a pathologist reviews the samples under the microscope to assess the type, size, appearance and maturity of the cells.

  • A bone marrow aspiration removes a small amount of liquid bone marrow from inside a bone.
  • A bone marrow biopsy removes a small piece of solid bone along with a small amount of bone marrow.

Cell Assessment. At the laboratory, a hematopathologist examines the blood and bone marrow cells under a microscope to determine their size, shape and type, and to identify other cell features. As part of this assessment, the hematopathologist will note any signs of MDS, such as one or more of the following:

  • Dysplasia (cells that are abnormal in size or shape) { An abnormal number of any type of blood cells (either too many or too few)
  • The percentage of blast cells in the bone marrow { An abnormally low or high number of cells in the bone marrow
  • Presence or absence of ring sideroblasts (red blood cells containing rings of iron deposits)
  • The extent of bone marrow fibrosis (scarring) if present
  • Presence of blast cells in the blood (blast cells are normally not found in the blood)

The hematopathologist then performs additional tests to see if there are abnormalities in the chromosomes and genes of the cancer cells

Biomarker Testing. These laboratory tests examine the MDS blast cells from the blood and bone marrow to check for certain genes, proteins or other molecules to provide information about a person’s cancer. Each person’s cancer has a unique pattern of biomarkers. Biomarker tests for MDS include the following: 

  • Cytogenetic Analysis (Karyotyping): Each cell in the body has chromosomes that carry genes. Genes give the instructions that tell each cell what to do. Cytogenetic analysis is used to look for abnormal changes in the chromosomes in the MDS cells.   
  • FISH (Fluorescence In Situ Hybridization): This test is used to examine genes and chromosomes in cells and tissues. Doctors use FISH to find certain abnormal changes in the chromosomes and genes of the MDS cells.  
  • Next-Generation Sequencing (NGS): This test looks for mutations in the genes of MDS cells. Certain mutations are markers that can help doctors identify a patients MDS subtype and predict how the disease will progress.   

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