Mandibular mass as the presenting manifestation of IgM myeloma in a 22-year-old man

We report here the youngest known IgM myeloma patient to have presented wit h a mandibular mass. A 22-year-old Chinese man sought medical attention due to a mass over his right mandible that had been growing progressively for 6 months. A solitary osteolytic lesion in the right mandible was identified radiologically. Incisional biopsy revealed the presence of plasma cells of monoclonal origin, as evidenced by the exclusively positive staining of th e kappa light chain. The diagnosis of multiple myeloma with mandibular invo lvement was confirmed by bone marrow examination. Further tests, including immunoglobulin electrophoresis and assay of the serum levels of kappa and l ambda light chains, demonstrated that his myeloma was of the IgM, kappa sub type, The patient achieved a nonsustained partial response to six courses o f melphalan and prednisolone therapy and palliative radiotherapy.