Imaging Pearls ❯ Musculoskeletal ❯ Extramedullary Hematopoiesis
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- “Extramedullary hematopoiesis (EMH) refers to an abnormal condition in which the bone marrow is not able to maintain adequate hematopoietic function, and hence, other locations in the body start compensatory hematopoiesis. Decreased or ineffective marrow hematopoiesis results from various pathologic conditions such as anemia and hemoglobinopathies [eg, severe hypochromic anemia, pernicious anemia, megaloblastic anemia, thalassemia, sickle cell disease ,myelophthisic disorders [eg, hematological malignancies, myelofibrosis, myelosclerosis, storage disorders, granulomatous diseases, osteoporosis, diffuse metastases, or peripheral hemolysis (eg, hemoglobinopathies, hereditary spherocytosis, autoimmune hemolytic anemias).”
Extramedullary Hematopoiesis: A Forgotten Diagnosis and aGreat Mimicker of Malignancy
Daniel Fadaei Fouladi, Elliot K. Fishman, and Satomi Kawamoto
J Comput Assist Tomogr. 2023 in press - “In over 85% of patients with EMH, liver, spleen, and lymph nodes serve as the secondary sites of the hematopoiesis, followed by the paraspinal space in 5% of patients and the retroperitoneum in less than 2% of patients. Other rare sites of EMH include the pelvis (eg, presacral region, prostate), intraabdominal locations (eg, the gastrointestinal tract, adrenal glands, omentum, mesentery, peritoneum), head and neck, and central nervous system (eg, nasopharynx, paranasal sinuses, middle ear, lacrimal glands, thyroid, peripheral and cranial nerves, spinal canal), urinary system (eg, urinary tract, kidneys, prostate), skin, and breast.”
Extramedullary Hematopoiesis: A Forgotten Diagnosis and aGreat Mimicker of Malignancy
Daniel Fadaei Fouladi, Elliot K. Fishman, and Satomi Kawamoto
J Comput Assist Tomogr. 2023 in press - The presacral area is the third most common site of EMH after the liver-spleen and thoracic paravertebral location. Patients are usually asymptomatic or report nonspecific symptoms. Similar to paraspinal EMH,most patients have an underlying hematologic disorder. Therefore, related osseous features such as periosteal elevation, cortical interruption, and medullary expansion usually are present at the time of the imaging study. On CT, presacral EMH typically presents as a well-marginated, round, or lobulated solid mass with interspersed fat, located adjacent and anterior to the sacrum. The normal contour of the sacrum is generally preserved owing to the pliable and soft nature of the EMH tissue. However, the mass effect of an adequately large lesion may displace the rectum. Other imaging findings follow the general rules for the EMH masses occurring in other parts of the body.
Extramedullary Hematopoiesis: A Forgotten Diagnosis and aGreat Mimicker of Malignancy
Daniel Fadaei Fouladi, Elliot K. Fishman, and Satomi Kawamoto
J Comput Assist Tomogr. 2023 in press - “Extramedullary hematopoiesis is one of those uncommon disease processes that can produce many imaging findings potentially resembling malignancy and may cause diagnostic challenges with other more serious resembling conditions such as metastases or lymphoma or other malignant conditions. The patient's underlying conditions predisposed to EMH and recognizing the imaging features of EMH, in particular typical location and imaging appearance, are helpful in making the correct diagnosis.”
Extramedullary Hematopoiesis: A Forgotten Diagnosis and aGreat Mimicker of Malignancy
Daniel Fadaei Fouladi, Elliot K. Fishman, and Satomi Kawamoto
J Comput Assist Tomogr. 2023 in press