Myelogram (cytomorphological study of bone marrow)

Taking biomaterial

To perform a myelogram, a red CM is required. A sample can be obtained by puncture of the sternum (sternal puncture), biopsy of the ilium (trephine biopsy), calcaneus, femur or tibia.

The first two procedures for taking a sample of biomaterial in hematology are used most often. Trephine biopsy allows you to obtain a large volume of biomaterial for research. Taking bone marrow samples from the heel and other leg bones is used in newborns and young children.

Indications and contraindications

The purpose of the CM study is to identify hematopoiesis disorders. A myelogram study is indicated for:

• anemia (except iron deficiency) and cytopenias;
• causeless increase in ESR in the general blood test;
• acute and chronic leukemia;
• erythremia;
• myeloma;
• lymphogranulomatosis and non-Hodgkin's lymphomas;
• metastasis of malignant tumors to bones;
• hereditary diseases (Nimman-Pick, Gaucher, Urbach-Wiethe diseases);
• splenomegaly of unknown origin.

Bone marrow puncture is performed to establish the stage and phase of leukemia, their differential diagnosis with leukemoid reactions. A myelogram study is indicated to determine the histocompatibility of the bone marrow of the donor and recipient.

Sternal puncture or trephine biopsy is contraindicated in patients with acute myocardial infarction, stroke, during an attack of angina, suffocation, or during a hypertensive crisis.

How bone marrow donation works: myths, fears, side effects

For transplantation, compatibility of blood groups and Rh factors is not necessary; genetic compatibility is more important. Among an ideally suitable unrelated donor and a related donor who does not match on all points, doctors will most likely choose the latter, because with it there is a lower probability of refusal to donate.

Sometimes 50-70 donors are suitable for a patient at once, but it happens that the “genetic twin” is not in the registry at all. In the latter case, you can try to organize donor campaigns so that more people undergo typing, but in any case, if a suitable donor is not in the bank, it will not be possible to help the patient. Every year at least three thousand people die because they could not find a suitable donor.

A patient and donor with the same ethnic background are more likely to be a match. The more people undergo typing, the more different genetic data there are in the registries, which means the higher the likelihood of patient and donor compatibility.

According to the American company Be The Match, the people who have the most problems finding a bone marrow donor are people of color, Indians, Alaska Natives, Asians, Native Hawaiians and other Pacific Islanders, Hispanics and mestizo. The American Institute of Justice reports that African Americans who do not have a related donor find a match only 25% of the time, and that if a donor is found, 80% of the time it is the only option on the registry. For Asians this figure is 40%, for Latin Americans - 45%, for Europeans - 75%. The specific percentage for mestizos is not given in the statistics, but the institute clarifies that for them the situation is much worse.

Why are bone marrow donors needed?

More than 5 thousand Russians require bone marrow transplantation annually, of which 4,214 are needed for adults and 900 for children. In Russia there is no general data register for donors; each bank counts its donors itself. According to oncologist-hematologist Sergei Semochkin, the largest stem cell bank in Russia is located in Kirov. There are 35,787 people registered there.

Another large registry of bone marrow donors in our country is managed by Rusfond - the National Register of Bone Marrow Donors named after Vasya Perevoshchikov. It has existed since 2013 and unites 12 regional Russian registers and one Kazakh one. As of October 31, 2021, there were 29,178 bone marrow donors.

There are 35.6 million people registered in the world bone marrow bank (Bone Marrow Donors Worldwide). However, it is difficult to find a donor compatible with a Russian there - in our country there are many nationalities and genetic combinations that are not found anywhere else in the world. The likelihood that a Russian person will find a suitable donor in the domestic registry is higher than in foreign ones.

Semochkin gives an example that often Caucasians cannot find their “genetic twin” in the European database. But they have more children in the family, so the likelihood of finding a related donor is higher. Small ethnic groups, for example, residents of the Far North, also have a huge problem with finding donors. As a rule, they fail to find a donor.

The only solution to the problem is for as many people of different nationalities as possible to join the national register. As Semochkin explains, the cost of cell transplantation and all other procedures for a Russian patient with a Russian donor does not exceed 160,000 rubles. At the same time, procedures and transplantation with a donor from a European bank require about 20,000 euros. The state cannot allocate that kind of money, and patients, as a rule, do not have it either - funding falls on charitable foundations.

How to become a donor?

In Russia, any healthy citizen of the Russian Federation without chronic diseases aged 18 to 45 years, and in some cases up to 50 years, can become a donor. Age matters: the younger the donor, the higher the concentration of cells in the transplant and their “quality”.

MGIMO master's student Irina became a bone marrow donor at the end of October this year. Before that, from the age of 18, she regularly donated blood and platelets to donor organizations. Three years ago, she read Valery Panyushkin’s column “Meeting” about how the donor and recipient met, and finally decided to donate bone marrow.

The first step is donating blood for typing. This can be done in any of the large private medical laboratories or in the laboratories of some medical centers or registries. You can view the full list of centers that allow you to get to Rusfond Bank here.

Irina chose the National Medical Research Center for Hematology. There she donated about 10 milliliters of blood for typing and signed an agreement to join the register. It does not oblige the donor to anything - you can refuse at any time. But this is important for the recipient - 10 days before the stem cell transplant, high-dose chemotherapy is carried out, which completely destroys the hematopoietic and immune systems. Therefore, a last-minute refusal can be disastrous for someone waiting for a transplant.

A month and a half after typing, Irina received a message by email that everything was fine with the tests and she was included in the register.

Preparation for the procedure

The procedure for taking BM is common in hematology. No special preparation of the patient for sternal puncture or trepanobiopsy is required.

Preparation for manipulation differs little from preparation for other minimally invasive procedures:

• the patient must be examined before the procedure (complete blood count, coagulogram);
• Anticoagulants and antiplatelet agents, as well as all other medications except vital ones, are canceled within a few days;
• the patient should not eat or drink for several hours (if the procedure is scheduled for the afternoon, the patient needs a light breakfast in the morning);
• 2 hours before the procedure, you need to empty your intestines, and immediately before it, you need to empty your bladder;
• if there is hair at the site of the future skin puncture, it is shaved off.

It is necessary to notify the doctor if the patient has any allergies, especially if it is an allergic reaction to local anesthetics.

On the day of biomaterial collection, the patient should not be prescribed other procedures or surgical interventions. If there is a strong feeling of fear, the patient should take sedatives half an hour before the procedure, which should be reported to the doctor. Sternal puncture and trepanobiopsy are not pleasant manipulations, but they are also difficult to classify as painful.

The puncture site of the skin and periosteum is treated with a local anesthetic, so pain is not felt in this place.

Immediately before the procedure, informed consent for the manipulation is taken from the patient: the course of its implementation, as well as possible complications after it, are explained to him. If the puncture is to be performed on minor children, informed consent is taken from their parents or other legal representatives.

Before the procedure

Tell the healthcare professional if you have blood clotting problems or are allergic to:

• chlorhexidine (used in liquids that kill germs);
• local anesthetics (medicines that numb an area of ​​the body);
• latex;
• adhesive materials such as tape or glue.

Ask your doctor about your medications

You may need to stop taking some of your medications before the procedure. Talk to your doctor about which medications you can stop taking. Below are some common examples.

Anticoagulants (blood thinners)

If you are taking blood thinners (which affect blood clotting), talk to your doctor before your procedure to find out if you should stop taking them.

Do not stop taking blood thinners without talking to your doctor.

Review the resource Common Medicines Containing Aspirin and Other Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) or Vitamin E. It provides important information about medications that should be stopped before your procedure and what medications can be substituted for them.

to come back to the beginning

Carrying out a bone marrow puncture

The patient is placed on the couch: for sternal puncture - on his back (a cushion is placed between the shoulder blades), for trepanobiopsy - on the right side or stomach. The puncture site is treated with an alcohol solution of iodine and anesthesia is performed using local anesthetics.

To carry out the manipulation, you need special instruments: a Kassirsky needle (for sternal puncture) or a trocar needle with a mandrel (for trepanobiopsy). At the free end of the trocar there are notches that play the role of a kind of “cutter”. Using this “cutter,” the outer layer of the bone is “drilled” using screwing movements.

During sternal puncture, the needle is inserted between the third and fourth ribs along the midline. During trepanobiopsy, a puncture of the skin and ilium is made in the area where the bone crest is located, usually to the left of the spine: this makes it easier for the doctor to carry out the manipulation.

In young children, the sternum is too thin and soft, so there is a possibility of a through puncture, which is an unfavorable complication. For this reason, a bone marrow sample is taken from the femur or tibia in children, and from the heel bone in newborns. Bone other than the sternum is also chosen for biopsy in older people with severe osteoporosis and in people taking long-term corticosteroids (due to the risk of sternum fracture).

The collected punctate (biopsy) is removed from the needle and placed on a glass slide (for cytological examination) or in a bottle with formaldehyde (for histological examination). To prevent coagulation of the liquid part of the bone marrow on the glass slide, fixatives are added to the punctate.

The dimensions of the biopsy specimen taken should allow obtaining sections for examination with an area of ​​at least 2×20 mm or 3×15. When performing a puncture (biopsy), it is very important to take bone marrow from the bone marrow cavity. If the majority of the specimen is occupied by periosteum or subcortical bone marrow cells, a full histological examination will not be carried out: examination of 5 or more bone marrow cells is required to make a conclusion.

After taking the biomaterial, the needle is removed from the bone, the puncture site is treated with an antiseptic, a sterile napkin is applied and sealed with a plaster.

Components of the procedure[edit]

Microscopic section of bone marrow biopsy (stained with H&E).
Preferred sites for the procedure Bone marrow samples can be obtained by aspiration and core biopsy.
Sometimes the bone marrow examination includes both an aspirate and a biopsy. The aspirate produces semi-liquid bone marrow, which a pathologist can examine under a light microscope and analyze using flow cytometry, chromosomal analysis, or polymerase chain reaction (PCR). A trephine biopsy is also often performed, which produces a narrow, solid, cylindrical piece of bone marrow, 2 mm wide and 2 cm long (80 μl), which is examined under a microscope (sometimes using immunohistochemistry) for cellularity and infiltrative processes. Aspiration using a 20 ml syringe yields approximately 300 µl of bone marrow. [1] Volumes greater than 300 µL are not recommended as this may dilute the sample with peripheral blood. [1] Comparison

All cells are not always represented by aspiration because some, such as lymphoma, adhere to the trabecula and thus may be missed by simple aspiration.

Possible complications

Taking a bone marrow biopsy is considered a safe procedure. If it is performed by an experienced doctor and in compliance with all the rules, complications after it are very rare. These rare consequences include:

• infection of the puncture site;
• bleeding;
• through puncture or fracture of the sternum;
• fainting and shock in hysterical patients.

To avoid possible consequences, the doctor must strictly follow all stages of the procedure, and before it, conduct a confidential conversation with the patient.

Contraindications [edit]

A volunteer donates bone marrow for scientific research.

There are few contraindications to bone marrow examination. It is important to note that thrombocytopenia or bleeding disorders are not

are contraindications if the procedure is performed by a qualified physician. [3] Bone marrow aspiration and biopsy can be performed safely even in conditions of extreme thrombocytopenia (low platelet count). If there is a skin or soft tissue infection on the thigh, another site for bone marrow testing should be chosen.

Recovery after manipulation

The procedure itself lasts no more than 15 minutes. After taking the samples, the patient is under medical supervision for an hour: pulse, blood pressure, and temperature are monitored. If no complications are found within an hour, the patient is sent home. For pain, patients can take painkillers.

Since dizziness and fainting are possible after the procedure, examined patients are prohibited from driving on this day. The risk of bleeding from the skin puncture site is the reason for the prohibition from performing heavy work, playing sports or drinking alcoholic beverages for several days after the procedure.

To prevent infection of the skin puncture site, it is necessary to promptly change napkins and treat the wound with antiseptics. Until the wound heals, it is prohibited to visit public pools, saunas, or swim in the river.

Cytological and histological examination

Bone marrow smears are prepared immediately after puncture collection. The biopsy specimen for histological examination is preserved in special solutions. In the laboratory, histological sections are prepared from the biopsy material, stained and evaluated. At the same time, they try to prepare as many CM microslides as possible, especially in hypoplastic processes, when the samples taken are very poor in cellular elements. Cytological examination is carried out on the day of sample collection; histology requires up to 10 days.

During a cytological examination, myelograms are assessed:

• number and ratio of different types of cells;
• pathological changes in the shape, size and structure of cellular elements;
• type of hematopoiesis;
• cytosis;
• bone marrow indices;
• the presence of specific cells.

The result of a cytological study has the form of a table of three columns: the first contains the names of cellular elements, the second - the indicators determined in the BM samples, the third - the reference (normal) quantitative or percentage indicators.

Modern methods of treatment

“The main type of treatment,” says oncologist Alexander Seryakov, “is a neurosurgical operation in which the tumor is completely removed and decompression (removal of compression) of the spinal cord is performed.
Micro-neurosurgical techniques, intraoperative neuroimaging and neuronavigation are often used. For malignant tumors of the spinal cord, in addition to surgical treatment, the patient may be prescribed chemotherapy and radiation therapy (stereotactic radiotherapy and radiosurgery using linear accelerators of the CyberKnife type).

Normal myelogram

In a bone marrow sample from a healthy person, no more than 2% of stromal cells are present: fibro- and osteoblasts, adipocytes, endothelial cells. Among the cellular elements of the parenchyma, undifferentiated stem, blast (young) and mature cells are found. The number of blasts does not exceed 1.7%.

Five cell lineages are found in the BM:

1. Erythroid (represented by erythroblasts, pronormocytes, normocytes, reticulocytes and erythrocytes).
2. Platelet (this includes megakaryoblasts, promegakaryocytes, megakaryocytes and thrombocytes).
3. Granulocytic (represented by myeloblasts, promyelocytes, myelocytes, metamyelocytes, band and segmented neutrophils, basophils and eosinophils).
4. Lymphoid (this includes lymphoblasts, prolymphocytes and lymphocytes).
5. Monocytic (consists of monoblasts, pronormocytes and monocytes).

Cells of different germs have their own structural features and properties, for example, sensitivity to acids, alkalis or other chemical compounds. These distinctive features are used when studying CM samples, using various dyes to process smears and sections.

In addition to the cytological composition of BM, the rate of their maturation is also important. It is determined by determining the ratios (indices) between maturing and mature cells:

• neutrophil maturation index (normal - 0.6-0.8);
• erythroblast maturation index (normal - 0.8-0.9);
• the ratio of white and red sprout cells (the norm is 3-4:1).

When studying trephine biopsy, the relationship between the BM parenchyma, adipose and bone tissue in sections is also determined. Their ratio is considered normal: 1:0.75:0.45. Violation of these ratios indicates bone marrow pathology. Histological examination is diagnostically more significant than cytological examination for BM hypoplasia, leukemia and cancer metastases in the bones.

4. Bone marrow biopsy results

Bone marrow biopsy results are usually ready within a week.

The following indicators are considered the norm:

• Bone marrow has normal amounts of fat, connective tissue, and iron. Normal ratio of adult and growing bone marrow cells.
• There are no signs of infection.
• There are no cancer cells such as leukemia, lymphoma or multiple myeloma.
• There is no spread of cancer cells from other affected areas.

Deviation from the norm:

• Bone marrow cells with pathology.
• The ratio of the number of different cells is disturbed.
• Bone tissue with pathology.
• Too much iron or too little iron (iron deficiency anemia).
• There are signs of infection.
• Cancer cells (leukemia, lymphoma, or multiple myeloma) are present.
• The bone marrow is replaced by scar tissue.

Depending on the results of a bone marrow biopsy or spinal tap, the doctor may prescribe additional examinations, select or adjust a treatment regimen, or, conversely, make sure that everything is in order with your health.