Plasma cell neoplasia in a single host: a mosaic of different protein-producing cell types.

The peritoneal plasma cell neoplasias that develop in strain BALB/c mice after the injection of adjuvant-staphylococcus mixtures or mineral oil alone appear in the form of multiple nodules in the mesentery and on peritoneal surfaces. Experiments were done to determine if these nodules were metastases or multiple primary neoplasms. Nodules or pieces of masses were transplanted subcutaneously by the trochar method or by insertion of tissue under the kidney capsule from 6 primary cases and parallel transplant lines were established. The serum and urinary protein abnormality (a stable heritable characteristic) of each of the various transplant lines was characterized by agar gel electrophoresis and immunoelectrophoresis. Different protein-producing lines were found in 3 cases; in one case 5 different protein-producing lines were isolated. Two different lines were found for each of the other 2 cases. When transplantation studies were begun early, it was demonstrated that the nodules were multiple primary plasma cell neoplasms; when delayed, only one protein-producing plasma cell neoplasm was found.