Preoperative Clinical and Hematological Parameters in the Differential Diagnosis of Uterine Smooth Muscle Tumor of Uncertain Malignant Potential (STUMP) and Leiomyoma: A Retrospective Study

Purpose Uterine smooth muscle tumors of uncertain malignant potential (STUMP) are a rare tumor group that falls between benign and malignant uterine smooth muscle tumors. Our study aimed to compare the preoperative characteristics of patients diagnosed with STUMP and leiomyoma and to determine parameters that can be used in differential diagnosis. Material and Method: This retrospective, cross-sectional study included 73 patients who underwent surgery between 2015 and 2023 with a preliminary diagnosis of uterine myoma and whose final pathology results were either STUMP (n = 32) or leiomyoma (n = 41). Demographic data, tumor characteristics, surgical procedures, biochemical (CA-125, LDH), and hematological parameters (hemogram, NLR, MLR, PLR, SII, SIRI) were compared. Results STUMP patients were more frequently seen at an older age (p = 0.040) and in the postmenopausal period (p < 0.001) compared to the leiomyoma group. Serum LDH levels were significantly higher in the STUMP group (p = 0.017). Lymphocyte count was higher in the STUMP group (p < 0.005), and PLR was higher in the leiomyoma group (p = 0.003). There were no significant differences in NLR, MLR, SIRI, and SII. Conclusion Serum LDH levels, lymphocyte counts, and PLR values ​​may be potential biomarkers for distinguishing STUMP from leiomyoma. These simple and accessible tests may contribute to preoperative clinical decision-making.