Abstract / Summary
Abstract Background: Uterine leiomyomas are common benign uterine neoplasms that may present with menorrhagia, pelvic pain, or abdominal discomfort. Although the diagnosis is usually established histomorphologically, immunohistochemistry may be useful in selected cases with atypical or degenerative features. Objective: To characterize the immunohistochemical expression of smooth muscle actin (SMA), desmin, CD10, and Ki-67 in histologically confirmed uterine leiomyomas and compare staining patterns between usual leiomyomas and leiomyomas with secondary changes. Materials and Methods: This prospective cross-sectional descriptive study included 50 histologically confirmed cases of uterine leiomyoma. Tissue sections were stained immunohistochemically for SMA, desmin, CD10, and Ki-67. Staining intensity and distribution were assessed using a predefined scoring system. Findings were summarized using frequencies, percentages, means, and standard deviations. Differences in marker expression between usual leiomyomas and leiomyomas with secondary changes were evaluated using appropriate comparative statistical tests, with statistical significance set at p < 0.05. Results: SMA and desmin were expressed in all 50 cases (100%). Strong SMA expression was observed in 45 cases (90%), while moderate desmin expression was identified in 26 cases (52%). Weak CD10 expression was present in 15 cases (30%). Ki-67 showed focal positivity in three cases (6%), with a mean labeling index of 0.3%. Histologically, 32 cases (64%) were classified as usual leiomyomas and 18 (36%) as leiomyomas with secondary changes. Strong SMA expression was observed in 29 of 32 usual leiomyomas (90.6%) and 16 of 18 leiomyomas with secondary changes (88.9%); this difference was not statistically significant (p = 1.00). Strong or moderate desmin expression was observed in 13 usual leiomyomas (40.6%) and five leiomyomas with secondary changes (27.8%), with no statistically significant difference ( p = 0.54). Conclusion: SMA and desmin were consistently expressed in the evaluated uterine leiomyomas, whereas CD10 expression was less frequent and Ki-67 labeling was generally low. The observed staining patterns provide descriptive information on smooth-muscle differentiation and proliferative activity in leiomyomas. However, because the study did not include diagnostic comparator lesions or longitudinal follow-up, the findings do not establish the diagnostic accuracy or prognostic value of these markers. Further studies involving leiomyosarcomas, endometrial stromal tumors, and other relevant uterine lesions are required to determine their diagnostic and prognostic utility.