Massive extramedullary disease progression in a patient with stable multiple myeloma during G-CSF priming for...

High dose therapy followed by autologous peripheral blood progenitor cell (PBPC) transplantation has recently become an encouraging treatment option for younger patients with multiple myeloma (MM). The influence of the growth factors used for progenitor mobilization on myeloma cells is not known. We report on a patient suffering from IgG kappa myeloma who had been in stable, very good partial remission for seven months after standard therapy until PBPC mobilization with granulocyte-colony stimulating factor (G-CSF, Filgrastim) was initiated. Massive extramedullary disease progression occured coincidentally with the administration of G-CSF. The case suggest the possibility of myeloma stimulation by G-CSF during PBPC mobilization.