Abstract: Extramedullary plasmacytoma (EMP) is a rare tumor characterized by proliferation of monoclonal plasma cells,  often occurs in the head and neck, followed by gastrointestinal and skin. Diagnosis is based on biopsy, which is the only accurate and reliable method. EMP is needed to discriminate with similar diseases. Radiotherapy is the preferred treatment method of EMP, because it has a higher radiation sensitivity. Sometime we can choose comprehensive treatment because of illness need. Hematopoietic stem cell transplantation is not as the preferred treatment option because of transplant rejection.

Key words: Plasmacytoma, Diagnosis, Radiotherapy, Prognosis