PD
‐
L1
Expression in Uterine Mesenchymal Tumors: A Comparative Immunohistochemical Analysis
Fajrin Mammadova Bahitli, Levent Akman, Gurdeniz Serin, Mert Acar, Nuri Yildirim, Osman Zekioglu, Mustafa Cosan Terek, Erdem Goker, Ahmet Aydin Ozsaran ABSTRACT
Objective
To evaluate and compare programmed cell death‐ligand 1 (PD‐L1) expression across benign and malignant uterine mesenchymal tumors using immunohistochemical analysis.
Methods
This retrospective study included 100 patients who underwent hysterectomy for uterine mesenchymal tumors at a single tertiary center between 2000 and 2022. Cases included leiomyoma (LM; n = 20), leiomyosarcoma (LMS; n = 20), low‐grade endometrial stromal sarcoma (LG‐ESS; n = 20), high‐grade endometrial stromal sarcoma (HG‐ESS; n = 20), and endometrial stromal nodule (ESN; n = 20). Immunohistochemical staining was performed using the PD‐L1 (22C3) antibody, and PD‐L1 expression was evaluated using the combined positive score. Clinicopathological parameters and PD‐L1 expression were compared among tumor subtypes.
Results
Patients with HG‐ESS demonstrated a significantly higher mean age at diagnosis compared with the other histopathological subtypes. PD‐L1 expression was detected in 9 (45%) LMS, 10 (50%) HG‐ESS, 3 (15%) LG‐ESS, and 1 (5%) ESN cases, whereas no LM cases demonstrated positivity. PD‐L1 expression rates were significantly higher in LMS and HG‐ESS than in LM, LG‐ESS, and ESN cases ( p < 0.0001). Combined group analyses also demonstrated significantly higher PD‐L1 expression rates in the combined LMS/HG‐ESS group compared with the LG‐ESS group and the combined LM/ESN group ( p < 0.0001).
Conclusion
These findings demonstrate increased PD‐L1 expression in aggressive uterine mesenchymal tumors; however, the clinical and therapeutic significance of these immunohistochemical findings remains unclear. Further studies integrating PD‐L1 expression with clinical findings and treatment outcomes are needed to determine the potential therapeutic relevance of PD‐L1 in these neoplasms.