[Rare monoclonal immunoglobulins, and analysis of their biological and clinical value].

Under rare monoclonal immunoglobulins we understand double or multiple formations in the same patient and above all the appearance of fragments, semimolecules or free heavy chains. Among our material of 309 cases of monoclonal immunoglobulins we could five times establish such findings. The cases in question were twice the combination of complete molecules, in three cases we saw fragment formations, partly in combination. By evaluation of literature and on the basis of an own observation we come to the determined result that these anomalous formations of fragments--which by all means may be called real paraproteins--must represent products of an incomplete synthesis. This anomaly is the functional expression of the structural changes concomitant with the cancerisation of the cell. Double and multiple formation is by no means at the same time bi- or oligoclonality. Our findings are discussed under these aspects.