What does small m protein and IgG lambda spike mean?

Monoclonal M-spikes. Antibodies such as igg are usually polyclonal. This means that many different b-cells are making antibodty with many different binding specificities. Monoclonal (m-spikes) suggest that the origin of the antibody is from one clone of blood cells, all originating from a sinle progenitor. This could mean a pre-malignant or malignant populations of cell are present.