Immunohistochemical Expression of Progesterone Receptor and B-cell Lymphoma-2 Antigen in Uterine Leiomyomas in a Southwestern Nigerian Teaching Hospital

Background: Uterine leiomyoma is the most common benign smooth muscle tumor of unknown aetiology. Progesterone may contribute to leiomyoma growth through the induction of B-cell lymphoma-2 (BCL-2) protein in leiomyoma cells. This study aims to determine the patterns of Bcell lymphoma-2 (BCL-2) and progesterone receptor (PR) expression in uterine leiomyomas seen at LTH, Ogbomoso, over a five-year period using immunohistochemical techniques.Methods: This was a hospital-based retrospective study of histologically diagnosed leiomyomas in the histopathology department of a teaching hospital between January 2012 and December 2016. A total of 141 cases of uterine leiomyomas were semi-quantitatively analysed immunohistochemically for PR and BCL-2 antigens. Results: Immunohistochemical analysis showed that out of 141 cases studied, 74 (52.5%) and 118 (83.7%) were positive for BCL-2 and PR, respectively. Among the 141 cases, 23 (16.3%) were negative for both PR and BCL-2. There was a moderate positive correlation between the immunohistochemical expression of BCL-2 and PR antigens, with a p-value < 0.001 (Pearson correlation = 0.563). Conclusion: This study showed that the majority of women with leiomyomas expressed both progesterone receptor and B-cell lymphoma-2 antigens. Therefore, selective women with leiomyomas could benefit from progesterone receptor modulators instead of undergoing invasive procedures such as myomectomy or hysterectomy.