Sera from 60 apparently healthy women (mean age 40 years; a control group), 40 patients with a verified diagnosis of adenomyosis (mean age 41 years) and 42 patients with uterine corpus cancer (UCC) (mean age 58 years) were fractionated on magnetic beads with weak cation exchange surface, followed by an examination of the obtained fractions by time-of-flight mass spectroscopy (MS) with ma- trix-activated laser desorption/ionization. MS data analysis using classification algorithms, such as a genetic algorithm and a learning neural network, made it possible to construct mathematical models that were able to differentiate MS profiles of the above sample groups with a high specificity and a high sensitivity. The best values of the specificity and sensitivity of the classification models adenomyosis- control and UCC-control were 86.2, 93.8, 90.5, and 90.5%, respectively. Analysis of the statistical diagrams of these peak areas between different sample groups could identify 3 MS profile peaks for adenomyosis and 3 peaks for UCC