Immunohistochemical characterization of stromal leukocytes in ovarian endometriosis: Comparison of eutopic and ectopic endometrium with normal endometrium

Objective: To compare stromal leukocyte subpopulations in different phases of the menstrual cycle in eutopic and ectopic endometrium from women with ovarian endometriosis and in control endometrium. Design: Retrospective immunohistochemical study. Setting: Department of Pathology, Royal Victoria Infirmary, Newcastle-upon-Tyne, United Kingdom. Patients: Paraffin-embedded tissue blocks from 30 patients with endometriosis and 30 control blocks from patients undergoing hysterectomy for nonendometrial pathology were retrieved from archive files. Main Outcome Measure: Quantitative assessment of defined stromal leukocyte subpopulations in eutopic, ectopic and control endometrium at different stages of the menstrual cycle. Results: In the proliferative and early secretory phases, ectopic endometrium contained elevated numbers of CD45+, CD3+, and CD43+ cells but reduced percentages of CD68+ macrophages. The proportions of granulated cells were reduced in ectopic endometrium throughout the cycle. No differences were noted between eutopic endometrium from women with endometriosis and control endometrium. Conclusion: Differences between eutopic and ectopic leukocyte subpopulations with the exception of large granular lymphocytes may be due to the lack of cyclicity demonstrated by endometriotic lesions.