Abstract
Here we described a case of an asymptomatic 73 years-old female patient in geriatric routine consultation, whose laboratory testing showed hyperproteinemia with accompanying hyperglobulinemia. A diagnosis of BGUS was made only after a correlation among SPEP, densitometry tracing and IFE results was established, evidencing a second peak, that was less evident and not reported at first. These biclonal conditions are of very low incidence in the clinical laboratory, requiring the laboratory professional to have particular skills for their identification. As far as is known, clinical findings in BGUS are similar to those found in MGUS. However, they remain not well understood. Therefore, for an accurate diagnosis of BGUS, the clinical laboratory technician must be trained and sensitized to detect a second M - protein as a band or peak; taking in mind the possible different scenarios in heavy and light chain typing.