What is Myelophthisic Anemia?
Anemia is a condition where the body has less hemoglobin, red blood cells, or a lower-than-usual amount of blood. Anemia comes in different types and for different reasons. It is divided into three categories: microcytic, macrocytic, and normocytic. Myelophthisic anemia, a type of normocytic anemia, occurs when the production of red blood cells is inadequate due to bone marrow being crowded out by abnormal tissue. Normocytic anemia means the size of the red blood cells is normal. Other types of normocytic anemia include aplastic anemia, anemia as a result of long-term illness, and kidney disease-related anemia. Microcytic anemia is characterized by tiny red blood cells and includes iron deficiency anemia and thalassemia. Macrocytic anemias are characterized by exceptionally large red blood cells and include megaloblastic anemia.
Anemia can have no symptoms or mild to severe ones. Extreme cases can be challenging as they can limit the ability to carry out daily activities. Recent research found that about one-quarter of the world’s population has anemia, with iron deficiency anemia being the most common variety. Because anemia influences disease rates and death, it’s very important to diagnose and treat it as soon as possible.
Myelophthisic anemia specifically refers to a variety of anemia characterized by premature red blood cells appearing in the bloodstream due to abnormal tissue overcrowding the bone marrow. This condition results in reduced production of red blood cells in the marrow, which contrasts with other forms of anemia where the number of reticulocytes (immature red blood cells) usually increases due to blood loss or cell destruction. Other potential causes for this condition include a lack of essential nutrients, exposure to toxins, hormonal disorders, blood cancers, and bone marrow failure syndromes. We will further delve into myelophthisic anemia, discussing its frequency, causes, how it affects us, its complications, assessment, and how it’s managed.
What Causes Myelophthisic Anemia?
Myelophthisic anemia is a type of blood disorder that arises when normal bone marrow is replaced or squeezed out due to the growth of abnormal non-blood cells. Some of these abnormal cells could be due to spreading cancers like breast or prostate cancers, blood diseases, or conditions like granulomatous lesions, fat storage diseases, and primary myelofibrosis, which is a bone marrow disorder.
Several cases of cancers affecting the breast, prostate, and blood cells have been reported to seep into the bone marrow. Khan and team reported a case where breast cancer had spread to the bone marrow. What happens is that these cancer cells take up space, replacing the blood stem cells, leading to a decrease in all types of blood cells (a condition called pancytopenia), and making the body produce blood cells outside the bone marrow.
Bone marrow can also become fibrous (scarring or thickening) due to widespread infection by mycobacteria (a type of germ), immune diseases, kidney bone disease, or issues with the thyroid gland that is either underactive or overactive.
Risk Factors and Frequency for Myelophthisic Anemia
Myelophthisic anemia is a condition found in less than 10% of individuals who are affected by metastatic cancers. These cancers can include types like prostate, breast, and lung cancer.
Signs and Symptoms of Myelophthisic Anemia
Myelophthisic anemia is usually seen in patients who have a history of chronic illnesses like cancer, or long-lasting inflammation or infections. It can be linked with various types of cancer, including prostate, breast, and lung cancer, and even advanced-stage melanoma. These patients will start showing signs of anemia, such as extreme tiredness, weakness, shortness of breath, and difficulty with physical effort.
In a physical check-up, patients may display pale conjunctiva (the whites of the eyes), a heart rate that is faster than normal (tachycardia), and an enlarged spleen (splenomegaly). An important thing to note is that the spleen and liver may become larger with this form of anemia, a result of the body trying to create blood cells outside of the bone marrow because it’s no longer able to. Sadly, these patients are also more likely to bleed and get infected again due to lower numbers of blood platelets and white blood cells.
- History of chronic illnesses, e.g., cancer
- Symptoms of anemia, i.e., extreme tiredness, weakness, shortness of breath, and difficulty with physical effort
- Pale conjunctiva (whites of the eyes)
- Faster than normal heart rate (tachycardia)
- Enlarged spleen (splenomegaly)
- Possibility of an enlarged liver or spleen due to extra blood cell production outside of the bone marrow
- Heightened chances of bleeding and getting infections again
Testing for Myelophthisic Anemia
In order to identify and correctly diagnose myelophthisic anemia, a combination of lab tests, microscope examination of your blood, and a bone marrow biopsy need to be conducted. The lab tests will typically include a complete blood count, giving doctors a detailed picture of the white and red blood cells, hemoglobin, hematocrit, platelets, MCV, count of immature red blood cells, and the variety in red blood cell size.
In cases of myelophthisic anemia, it’s common to find a significantly reduced count of all cell types in the blood. This happens because the bone marrow, which is responsible for producing blood cells, is being invaded by cancerous cells or experiencing fibrosis, a type of tissue scarring. Usually, the MCV values remain normal and the counts of immature red blood cells are low.
Detailed examination of your blood under a microscope gives further insights. It might show abnormal red blood cells in a range of immature to defective shapes and sizes. You might have red blood cells that still have their nuclei, and some blood cells might have an unusual teardrop shape. Other abnormalities could include oversized platelets and immature white blood cells. When these young cells are present, it’s a sign of a condition known as leucoerythroblastic change.
Lastly, a bone marrow biopsy is performed. This test gives a clear picture of whether cancerous cells have invaded your bone marrow, or whether fibrosis has occurred due to diseases that cause inflammation or are immune-related.
Treatment Options for Myelophthisic Anemia
Myelophthisic anemia is treated differently depending on its underlying cause. For those with tumors, eliminating the cancerous tissue through ways like chemotherapy or radiation can help remove the tissue that’s taking up the space of blood cell-making cells. One fascinating case detailed how a patient with advanced melanoma – which was causing myelophthisic anemia – responded positively to a drug called pembrolizumab, an anti-PD-1 inhibitor. This is encouraging as it hints at an immune system component within the bone marrow. Other healthcare professionals have also reported potential links between the immune and skeletal systems.
Packed red blood cell transfusions are common as people with this condition have low hemoglobin levels. Additional treatments, such as platelet transfusions or medications that stimulate white blood cells, may be used if the patient has severe concurrent bleeding or infections.
If a patient has myelophthisic anemia due to primary myelofibrosis (a bone marrow disorder), using ruxolitinib – a Janus kinase inhibitor – can help. Recent studies have shown that the usage of ruxolitinib has survival benefits.
What else can Myelophthisic Anemia be?
When doctors are trying to diagnose a type of anemia called myelophthisic anemia, they first need to exclude other conditions that could be causing low red blood cell production. These conditions could include:
- Nutritional deficiencies (like lack of iron, vitamin B12 or folate)
- Anemia caused by chronic disease or inflammation
- Anemia caused by kidney disease
- Thyroid disorders (hypothyroidism or hyperthyroidism)
- Overactive parathyroid glands (hyperparathyroidism)
- Blood cancers (hematologic malignancies)
- Other causes for the bone marrow not functioning properly
The bone marrow can fail to produce enough blood cells for various reasons, such as some medications (like drugs used in chemotherapy), certain infections (like parvovirus B19 and EBV), immune diseases, pregnancy and even some genetic diseases.
When identifying the genetic diseases, doctors particularly look for Fanconi anemia, GATA 2 deficiency, and Schwachman-Diamond syndrome as these also result in a deficit of all types of blood cells, known as pancytopenia.
Diagnosing anemia can be complicated because there can be many underlying causes. However, a careful review of the patient’s blood smear test, bone marrow biopsy, and immunohistochemistry test can help doctors arrive at a diagnosis. One key point that can confirm the diagnosis of myelophthisic anemia is the production of red blood cells outside of the bone marrow (extramedullary erythropoiesis), often accompanied by leukoerythroblastosis, a condition where immature white and red blood cells are found in the blood. These characteristics differentiates myelophthisic anemia from conditions like aplastic anemia and pancytopenia.
What to expect with Myelophthisic Anemia
The outlook for myelophthisic anemia, a type of blood disorder, can differ greatly depending on what’s causing it. For example, if the condition is related to an advanced form of carcinoma (a type of cancer) that has spread to the bone marrow, the outlook isn’t very promising. In fact, research by Kwon JI suggests that when gastric carcinoma, or stomach cancer, spreads to the bone marrow, the outlook is extremely poor.
Possible Complications When Diagnosed with Myelophthisic Anemia
Patients could experience a number of complications. They may suffer from symptoms of significant anemia because there aren’t enough normal red blood cells circulating in the blood. Infections could happen due to a low white blood cell count, and excessive bleeding might occur due to a severe reduction of all types of blood cells. Further complications could come from an overactive spleen causing persistent low platelet count, and high blood pressure in the vein that carries blood to the liver.
- Severe anemia due to a low count of normal red blood cells
- Infections due to a low white blood cell count
- Excessive bleeding due to a drastic reduction in all types of blood cells
- An overactive spleen which results in persistent low platelet count
- High blood pressure in the vein that carries blood to the liver
Preventing Myelophthisic Anemia
It’s crucial for patients to understand that anemia has various causes and types. The most frequent one is iron-deficiency anemia, which can be addressed by taking iron supplements. However, other types such as myelophthisic anemia involve treating their root cause. Although the symptoms of different kinds of anemia, like fatigue, pale skin, a fast heart rate, and occasionally difficulty in breathing, are somewhat similar, it’s vital for patients to keep themselves informed and talk to their general doctor if they start to notice new symptoms like bleeding or recurrent infections.