Objective: Cesarean section scar endometriomas (CSSEs) are believed to be the result
of direct inoculation of the subcutaneous tissues or abdominal fascia with endometrial
cells during surgery as well as higher immune tolerance during pregnancy. The ectopic
endometrium exhibits multiple subtle, but biologically important, molecular abnormalities favoring increased production of estrogen, cytokines, prostaglandins, and metalloproteinases.
Patients and Methods: The present study was undertaken to immunohistochemically
study the expression of the nuclear estrogen receptors (ERs) alpha and cytoplasmic endothelial cell markers CD34 in 34 cases of CSSEs, 27 cases of ovarian endometriomas
(OEs) compared with 18 cases with late proliferative endometrium (PE) as control group < br />Results: The incidence of CSSEs is 0.39% in Mansoura university hospitals, the mean
total score (TS) of ERs-alpha and CD34 assessed by mean vascular density (CD-34 MVD)
were significantly increased (p < 0.001) in cases of CSSEs and OEs versus the control
group. There was a statistically significant increase in the TS of ERs-alpha (p < 0.001) in
cases of OEs versus CSSEs. On the other hand, there was no statistically significant difference in CD-34 MVD between cases of CSSEs and OVs. In cases with CSSEs, there was
no significant correlation (r 0.212, p 0.229) between TS of ERs-alpha and CD-34 MVD.
No significant correlations were noted between either ERs or CD-34 MVD and age of the
patients, parity, number of prior CSs, duration since the last CS(s) and size of CSSEs.
Conclusion: CSSEs are a multifactorial disease, both ERs alpha and CD34 may play a
role in the pathogenesis and maintenance of endometriosis. Obstetricians should keep in
mind measures to prevent transmission of endometrial cells during CS.