Introduction to myelofibrosis

Brief introduction: Myelofibrosis (MF) is a kind of myeloproliferative disease caused by collagen hyperplasia in bone marrow hematopoietic tissue, which seriously affects hematopoietic function. Primary myelin is also called "Sclerotosis of the bone marrow", "myeloid metaplasia of unknown cause". The disease has different degrees of myelofibrosis, as well as extramedullary hematopoiesis mainly in the spleen, followed by liver and lymph nodes. The typical clinical manifestation is juvenile-erythrocytic anemia, and there are more teardrop-shaped red blood cells. The bone marrow puncture often shows dry pumping, the spleen is often swollen, and has different degrees of bone sclerosis. Etiology: [Cause] has not been elucidated, some scholars believe that bone marrow fibrosis is caused by abnormal stimulation of hematopoietic stem cells, resulting in fibrous tissue hyperplasia, and even new bone formation, bone marrow hematopoietic tissue involvement eventually leads to hematopoietic failure. The main pathology of MF was changed to myelofibrosis and extramedullary hematopoiesis in spleen and liver lymph nodes. The occurrence of myelofibrosis occurs from the center to the outer periphery, starting from the proximal epiphysis of the spine, ribs, pelvis and femur and tibia, and then gradually spreading to the distal end of the extremities. 1) Early whole blood cell proliferation with mild myelofibrosis bone marrow cells showed varying degrees of proliferation. Red, granular, and megakaryocyte cell lines all proliferated, with megakaryocytes being the most obvious. The fat vacuoles disappeared and the reticular fibers increased, but the normal structure of the bone marrow was not affected. Hematopoietic cells account for more than 70%, and bone marrow stroma is mainly composed of soluble collagen. 2) Metaphase bone marrow atrophy and fibrosis stage fibrous tissue hyperplasia, accounting for 40% to 60% of bone marrow, hematopoietic cells account for 30%, megakaryocytes still proliferate. The trabecular bone is increased and thickened, and new bone formation is formed adjacent to the bone marrow. Each of the scattered hematopoietic regions is separated by a parallel bundle or spiral of matter formed by reticular fibers, collagen fibers, plasma cells, and stromal cells. 3) End stage of advanced myelofibrosis and osteosclerosis. It is mainly composed of bone trabecular bone hyperplasia, accounting for 30% to 40% of bone marrow. Both fibrous and osteosclerotic tissues were significantly proliferated, and the medullary cavity was narrow. Except for megakaryocytes, the hematopoietic cells of other lines were significantly reduced. In this period, the bone marrow matrix component is mainly composed of polymeric proteins, mainly expressing fibronectin, and the distribution of exogenous protein and TENASCIN is increased. Symptoms: [Clinical manifestations] Most of the diseases are hidden and progress is slow. Many patients are often diagnosed after months or years of symptom onset. The most common symptoms are fatigue, weight loss and spleen compression. At first, the general condition is still good, and gradually the symptoms of spleen enlargement, hypermetabolism, and anemia are aggravated. In the advanced stage, there may be bleeding symptoms. The main clinical manifestations are: 1) Spleen, hepatomegaly and splenomegaly are the most important clinical manifestations, and the incidence rate is almost 100%. Occasionally, the patient himself was found to have a lump in the left upper abdomen or was found during a physical examination. Some people think that the degree of spleen is related to the course of the disease. Every 1 CM under the spleen rib represents a one-year course. Due to the splenomegaly, the abdomen is often full or heavily stressed. The spleen touches solidly and generally has no tenderness; however, if the spleen grows too fast, local pain may occur due to local infarction of the spleen, and even a rubbing sound may be heard. 2) Most of the patients with systemic symptoms are fatigue, weight loss, heat, sweating and other symptoms. Appetite is generally or diminished. Late wasting is especially noticeable. 3) There is mild anemia in the early stage of anemia, which gradually worsens with the decrease of hemoglobin. The symptoms of pale, fatigue, weakness, shortness of breath after physical activity, and palpitations are obvious. 4) Early bleeding platelet count increased or normal, no bleeding symptoms. Late thrombocytopenia, the skin often has purpura or ecchymosis, may have nasal discharge. 5) Other minority patients may have unclear bone pain. Very few patients develop secondary gouty arthritis due to increased blood uric acid. [Diagnostic criteria] Domestic diagnostic criteria: 1. Spleen enlargement; 2. Peripheral blood and nucleated red blood cells can be seen in the peripheral blood. There are different numbers of teardrop-like red blood cells. There may be red blood cells in the course of the disease. There are different numbers of teardrops. Red blood cells, red blood cells, white blood cells and thrombocytopenia and decrease in the course of disease; 3, bone marrow puncture multiple "dry pumping" or "hypoplasia"; 4, spleen, liver, lymph node pathological sections show obvious proliferation of fibrous tissue; diagnosis IMF Must have the fifth item plus any two of the remaining four items and can exclude the secondary MF. 1. Blood: Hemoglobin is reduced, positive cells are positively pigmented anemia; white blood cells are more normal or increased, a few are reduced; platelets are reduced, and a small number of patients are significantly increased. See the classification of young particles, young red blood cells, basophils, teardrop-shaped red blood cells, polychromatic red blood cells. Reticulocytes increase (2% to 5%). 2. Bone marrow: bone marrow puncture is mostly dry pumping, bone marrow hyperplasia is mostly reduced, hematopoietic cells are significantly reduced, and non-hematopoietic cells can be increased. 3. Tissue biopsy: bone marrow: fibroblasts proliferate significantly. Liver and spleen: There is extramedullary hematopoietic foci. 4. X-ray examination: About 70% of patients have osteopetrosis; the trabecular bone boundary disappears and the appearance is frosted glass. 5. Genetic examination: Some patients have chromosomal abnormalities, but the Ph1 chromosome is negative. Others: serum alkaline luciferase, lactate dehydrogenase, uric acid, vitamin B12 can be increased. Diagnosis: Myelin should be identified with the following diseases: 1 Chronic myeloid leukemia: Both can have spleen, white blood cell count increases, peripheral blood appears granulocyte proliferation like neutrophils, late granulocytes, but slow age of onset Lighter, the white blood cell count is often more than 100,000/mm3, and there are fewer myelocytes in the blood. The deformity of red blood cells is not typical of myelin. Leukocyte alkaline phosphatase activity is reduced or eliminated and the ph' chromosome is distinguishable from myelin. 2 The disease must be distinguished from low-proliferative acute leukemia and other diseases that cause juvenile-erythrocytic anemia. Secondary myelin can be diagnosed from clinical manifestations or special examinations. Sometimes multiple sites, multiple bone marrow smears and biopsy are needed to exclude secondary myelin. Complications: Common complications include various symptoms caused by spleen compression, anemia, and bleeding. treatment: Read more...