[Incidence of accidentally discovered paraproteinemias among the patients of a hospital for internal diseases].

Covering a ten-year period (1970-1979), this retrospective study was performed to determine the frequency of unexpected paraproteinemia in hospitalized patients with various internal diseases. The survey was made possible by the fact that serum protein electrophoresis had been routinely performed in all patients upon admission. In 86 cases (0.66% of all admissions) monoclonal gammopathy was an unexpected finding. 5 out of these 86 cases (0.038% of all admissions) had malignant disease (2 patients with Bence Jones myeloma, 3 patients with Waldenström's macroglobulinemia), and 3 more cases had lymphoproliferative syndromes. In all other cases the abnormal serum protein findings corresponded to asymptomatic ("benign") paraproteinemias when first detected. In addition, the following statistical parameters were analyzed: distribution among immunoglobulin classes; sex; and concomitant diseases. A critical evaluation was possible in 67 cases of so-called idiopathic paraproteinemia.