Association of osteonecrosis of the jaws and POEMS syndrome in a patient assuming rituximab.

POEMS syndrome, is a rare condition characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal proteinaemia, and skin lesions. We report a rare case of a patient affected by Waldenström macroglobulinemia, who developed POEMS syndrome and who presented at the time of diagnosis with oral manifestations of the lymphoma and an osteonecrosis of the jaw (ONJ) after rituximab treatment. Although the etiology of ONJ is not known, it is likely that several factors are at play, including endothelial cell damage, decreased angiogenesis, and microvascular compromise. Our patient was treated with rituximab for a long period, and recent studies have demonstrated the possibility that rituximab, a monoclonal antibody directed against the CD20 can exert part of its anti-tumor action, through its action on angiogenesis. Although our report does not allow identification of rituximab as a new risk factor for the onset of the ONJ, further studies seem necessary to exclude a role of the antibody in the alterations of angiogenesis that could lead to the development of the syndrome after rituximab treatment.