[Non-secretory plasmacytoma. Bibliographic review and immunohistochemical study of a case]

After a brief examination of the recent literature on non-secretory multiple myeloma, the Authors describe the immunohistologic study (peroxidase-antiperoxidase method) of a case of truly non producing plasmacytoma, interesting because of the presence of a small polyclonal plasma cell population within the neoplastic clone. Several possible explanations are considered.