Immunopathological diagnosis of plasma-cell dyscrasia. Part I. "Primary" monoclonal gammopathy.

Two patients with "primary" plasma-cell dyscrasia, one with IgG kappa multiple myeloma and another with delta type light chain disease, are reported. Both of them presented extraosseous tumor mass on the forehead as an initial problem. They had moderate to severe anemia, accelerated ESR and multiple osteolytic lesions in the x-ray bone survey. They did not show prominent monoclonal spikes in serum electrophoregram and physiological immunoglobulins were not decreased. Repeated bone marrow aspirates on these two cases did not reveal definite plasmacytosis and pathological diagnosis was established by tumor biopsy. Immunopathological correlations were made, with an emphasis on rational analysis and interpretation of monoclonal proteins.