Extramedullary hematopoiesis is a compensatory mechanism by which red blood cells are produced outside the bone marrow when marrow production is insufficient to meet the body's demands.
Erythropoiesis occurs normally in an extramedullary fashion during gestation, with fetal blood being produced in the liver, lymph nodes, and spleen. Even though blood production normally shifts to the marrow before birth, the extramedullary hematopoietic connective tissues retain the ability to produce red blood cells and under certain conditions become active in blood production. Extramedullary hematopoiesis may occur in the spleen, liver, and lymph nodes, and less frequently is seen in the kidneys, pleura, breast, adrenals, skin, gastrointestinal tract, and dura mater.
Extramedullary hematopoiesis has been reported in severe anemias, in myelofibrosis and other infiltrative conditions of the marrow, in polycythemia Vera and after toxic damage to the marrow.
The sonographic appearance of extramedullary hematopoiesis has been infrequently cited'.' and may be confused with more common diagnoses. We present a patient with extramedullary hematopoiesis of the liver detected by ultrasound.
CASE REPORT
The patient is a 28-year-old female who has been followed with the diagnosis of polycythemia Vera for 12 years.