Overview of bone marrow necrosis
Bone marrow necrosis (BMN) is the in situ death of hematopoietic cells, which is secondary and has a variety of etiologies. It is characterized by fever, bone pain, and in some patients, reticulocytopenia and peripheral blood trichomonocytopenia. The male-to-female ratio is 2.46:1, age 4-70 years old, median age 38.5 years old, mainly young adults, rare in children.
Etiology
Seen in leukemia, myelofibrosis, sickle cell disease, lymphoma and various cancers, diver’s disease, megaloblastic anemia, myeloma, malignant histiocytosis, iron granulocytic anemia, hypovolemic shock, antitumor chemotherapy, radiation irradiation, sedation sulfathiazole, embolism, and so on.
Symptoms
The first symptoms are mainly bone and joint pain and fever, mostly occurring 2 days to 1 month before bone marrow necrosis. Osteoarthralgia is of acute onset with severe pain, usually located in the lower back. Fever is moderate to high, with indolent and flaccid fever, and up to 40℃ when combined with infection.
Examination
1. Blood test
After bone pain, there is often a decrease in the number of whole blood cells, and the peripheral blood shows juvenile granulocytes and juvenile erythrocytes.
2. Bone marrow examination
(1) Bone marrow aspiration smear cytomorphology examination, the extracted bone marrow fluid has various traits, which can be dark red, jam-like, rice soup-like or purulent, without particles, or sand-like particles, with dark red watery sample being the most common.
(2) Bone marrow biopsy reveals necrosis and gel-like formation of bone marrow tissue, focal hypoplasia, amorphous eosinophilic material, and bone marrow cavity filled with necrotic debris.
3. Imaging examination
(1) Radionuclide 99mTc myelography shows the reticuloendothelial component of the bone marrow, which corresponds to the area of hematopoietic tissue, and the hematopoietic tissue lesion >2cm can be shown. There is no radionuclide uptake in the necrotic area of the bone marrow, but residual bone marrow tissue can also be displayed in order to guide bone marrow aspiration to obtain information on the primary pathology.
(2) MRI shows altered signaling of bone marrow cellular components, fat, and water, and bone marrow necrosis shows an increased water component on MRI. The altered contrast of fat and cellular components can help diagnose the size of the necrotic area and guide biopsy of the remaining hematopoietic tissue, which can also help to understand the recovery of the hematopoietic tissue.
Diagnosis
1. Young adults.
2. Bone and joint pain and pressure, fever and progressive anemia are the main manifestations.
3. Liver, spleen and lymph nodes are enlarged.
4. Young granulocytes and young erythrocytes are seen in the peripheral blood.
5. Bone marrow smear and biopsy show typical bone marrow necrosis.
Treatment
1. Active treatment for the primary disease.
2. Symptomatic treatment
(1) Bone marrow necrosis caused by malignant diseases should be treated against the primary tumor.
(2) Antibiotics should be applied to those caused by inflammation.
(3) Improve microcirculation, prevent myelofibrosis and promote hematopoietic recovery in non-malignant diseases.
(4) Megaloblastic anemia should be supplemented with folic acid and vitamin B12.
(5) Blood transfusion, adrenocorticotropic hormone and antibiotic treatment can be used for those with unknown causes.