Abstract
A case of plasmacytoma of vertebral arch of the sixth thoracic vertebrae. M-component in serum and Bence-Jones protein in urea were very low levels. And tumor ceils were immature lymphoplasmacitic cells. But in immunohistochemical study monoclonal polypeptides of light chain of λ type was positive.Furthermore, ultrastructure revealed plasmacytes with extremly developed coiled and lammela rER, but golgi apparatus and mitochondria were not intact. These features revealed that the plasma cells synthesized polypeptides of light chain of λ type, but did not secret in serum. So we conclude that this case is non secretary light chain disease of λ type.
