• M-component

ABSTRACT. Sixty-four persons with M-components in serum were detected in a health survey of 6995 subjects in 1964. After 20 years, data could be obtained on all 64. The 45 who had died included two cases of myeloma and one of malignant lymphoma. One of the myeloma cases had started as chronic lymphatic leukemia. Three of the 19 persons alive had an increase in the size of the M-component and depression of the background immunoglobulin, but they could not be diagnosed as myeloma cases. One had a rather large but not increasing M-component and an excess of light chains. She could be a third case of myeloma in this series.