Retroperitoneal mass and spinal cord compression due to extramedullary haemopoiesis in polycythaemia rubra vera

The development of discrete masses of extramedullary haemopoietic tissue is well recognized in a number of diseases (Ward & Block, 1971); however, it has been described only rarely in the proliferative phase of polycythaemia rubra vera (Rice et al, 1980; Robitaille et al, 1985). Most cases of extramedullary haemopoiesis present with posterior mediastinal or extradural masses (Ward & Block, 1971) and spinal cord compression is also well documented with over 30 cases in the world literature (Cromwell & Kerber, 1978; Ligumski et al, 1978; Mann et al, 1987). The diagnosis of extradural extramedullary haemopoiesis is important since it responds well to radiotherapy (Sorsdahl et al, 1964; Cromwell & Kerber, 1978) and can otherwise lead to serious neurological sequelae or deat