The diagnosis of MDS ultimately depends on microscopic examination of bone marrow and the analysis of damage to the chromosomes, or DNA of bone marrow cells. MDS tends to produce nonspecific symptoms and the bone marrow biopsy will be necessary for diagnosis.
The diagnosis and prognosis of MDS includes the following:
- Review of medical history
- Physical exam
- Diagnostic testing
Review of Medical History
Your doctor will ask about your symptoms and medical history. Your answers may point in any of 3 directions: to red blood cells that suggest anemia, to blood clotting mechanisms if you are bruising or bleeding, or to the immune system if you are having persistent infections. Rarely, people may present during an acute infection that signifies an infection-fighting deficit. In this case, a persistent sore throat or nonhealing infection elsewhere may be the first sign of difficulty.
There may be little or nothing to discover from your physical exam. You may have bruising, an active infection somewhere in your body, or findings such as pale skin and a rapid heartbeat that suggest anemia. Your spleen, lymph glands, and/or liver may be enlarged.
General lab tests may include:
- Blood and urine tests—These tests will be done as a routine and may reveal abnormalities, but they will not be specific. A complete blood count (CBC) analyzes the number of blood cells by type to determine if they are within normal ranges.
- Peripheral blood smear—Your blood sample will be examined in the laboratory under a microscope. If you have MDS, some or all of your blood cells will be either abnormal or deformed when examined under magnification. The most common abnormality is one of quantity. In MDS, low amounts of one or more blood cell types may be present. Occasionally the number may be increased and the relative counts may fluctuate over time.
If there are abnormalities in your blood tests, your doctor will likely refer you to a hematologist (a blood disorder specialist), who will do a bone marrow biopsy.
A needle is inserted into the back of the pelvis to the right or left of the midline, or the sternum (breastbone). A sample of the bone marrow tissue is suctioned out for testing in 2 parts. The first part is called the aspiration where 1-2 teaspoons of bone marrow liquid is removed. The second part involves removing a small core of tissue (biopsy) to examine the architecture surrounding the cells. The exam of the bone marrow tissue will not only confirm a diagnosis, it will also characterize the type of MDS and provide treatment and prognostic information. Some of the aspiration material is also sent for molecular and chromosome analysis.
Cytology is the study of cells. The cytology of cancer cells differs significantly from normal cells, and doctors use the unique cellular features seen on biopsy samples to determine the diagnosis and assess the prognosis of a cancer. With MDS, the bone marrow produces enough cells, but the cells are abnormal and unable to function properly. Any or all of the cell types in the marrow may show abnormalities that will confirm your diagnosis with precision. However, a few cell types are critical to the final classification of the several forms of MDS:
- A blast is the most immature form of any of the cell types. More than 30% blasts in the bone marrow traditionally signifies the presence of acute leukemia.
- A ringed sideroblast is from the red blood cell series.
Tests can also be done to look at the cellular chromosomes. MDS can be diagnosed when there are missing or abnormal chromosomes.
International Prognostic Scoring System (IPSS)
WHO (World Health Organization) Scoring System (WPSS)
Staging is the process by which doctors determine the prognosis of a cancer that has already been diagnosed. Staging is essential for making a treatment plan. Several features of the cancer are used to arrive at a staging classification, the most common being the size of the original tumor, extent of local invasion, and spread to distant sites (metastasis). Low staging classifications imply a favorable prognosis, whereas high staging classifications imply an unfavorable prognosis.
Since MDS is a bone marrow disease, it can not be classified using the traditional staging method. Instead, there are 2 different staging systems used for MDS: International Prognostic Scoring System (IPSS) and WHO (World Health Organization) Scoring System (WPSS).
The IPSS rates three factors to stage MDS:
- Percentage of blasts in the bone marrow
- Chromosome abnormalities
- Patient blood counts
Patients are given a score for each of the 3 factors. The lower the score the better the prognosis. The scores are added together to get an overall IPSS score. There are 4 categories of IPSS scores:
- Low risk
- Intermediate-1 risk
- Intermediate-2 risk
- High risk
The IPSS scoring uses the following 5 classifications of bone marrow appearance:
- Refractory anemia with ringed sideroblasts (RARS)
- Refractory anemia (RA)
- Chronic myelomonocytic leukemia (CMML)
- Refractory anemia with excess blasts (RAEB)
- Refractory anemia with excess blasts in transformation (RAEB-t)
Each of these types has criteria for definition, including the presence of ring sideroblasts and the percentage of cells that are called blasts. In general, the greater the damage, the more the chromosomal damage, and the greater the number of blasts in the bone marrow, the greater the chance of progressing to acute leukemia.
This system uses three factors to score risk:
- Type of MDS based on 8 WHO classifications
- Chromosome abnormalities
- Patient need for transfusions
Once scored, patients are placed into one of 5 groups:
- Very low risk
- Low risk
- Intermediate risk
- High risk
- Very high risk
The WHO scoring systems uses the WHO classification system for type of MDS:
- Refractory anemia
- Refractory anemia with ringed sideroblasts
- Refractory cytopenia with multilineage dysplasia
- Refractory cytopenia with multilineage dysplasia and ringed sideroblasts
- Refractory anemia with excess blasts-1
- Refractory anemia with excess blasts-2
- Myelodysplastic syndrome, unclassified
- Myelodysplastic syndrome associated with isolated del(5q)
Prognosis is a forecast of the probable course and/or outcome of a disease or condition. Prognosis is most often expressed as the percentage of patients who are expected to survive over 5-10 years. Cancer prognosis is a notoriously inexact process. This is because the predictions are based on the experience of large groups of patients with cancer in various stages. Using this information to predict the future of an individual patient is always imperfect and often flawed, but it is the only method available. Prognoses provided in this monograph and elsewhere should always be interpreted with this limitation in mind. They may or may not reflect your unique situation.
The table below gives the 5-year survival rate and risk of leukemia according to IPSS risk groups.
The table below gives the median survival and risk of leukemia according to WPSS risk groups.
- Reviewer: Mohei Abouzied, MD
- Review Date: 12/2015 -
- Update Date: 12/20/2014 -