[Extramedullary hematopoiesis of thoracic and vertebral intraductal localization. Apropos of a case. Review of the literature].

The authors report a case of extramedullary haematopoiesis, presenting in the form of several tumor masses in the posterior mediastinum and in the vertebral canal. The patient presented with oedema in his lower limbs due to compression of the inferior vena cava by the mediastinal masses. The asymptomatic mass in the vertebral canal was detected by magnetic resonance imaging. The patient was first operated on to avoid spinal cord compression by the tumor and subsequently to relieve compression of the inferior vena cava. The masses removed from the vertebral canal and the mediastinum were found on histologic examination to be extramedullary haematopoiesis. The cause of the disease was unknown in this case. Such disease is often disclosed in the course of hemolytic anaemias or other medullar deficiency diseases as a compensatory phenomenon when the bone marrow fails. An other explanation is that it is a manifestation of a myeloproliferative disorder in which heterotopic pluripotential cells are transformed into haematopoietic cells. The authors review 88 cases reported in the world literature.