Clinicopathological correlations of peritoneal endometriosis and deep infiltrating endometriosis

Abstract

Objective

The present study aims to investigate the clinical and histopathological features of peritoneal endometriosis (PEM) and deep infiltrating endometriosis (DIE).

Methods

A total of 100 patients with PEM and DIE admitted to Dalian Women and Children’s Hospital/Dalian Women and Children’s Medical Center between October 2018 and December 2021 were selected as the study subjects. One hundred and thirty-one PEM specimens and 37 DIE were collected, 22 cases of these patients’ eutopic endometrium were used as control (15 in PEM, seven in DIE). The present study mainly analysed the pelvic distribution, the histopathological and immunohistochemical features and peritoneal invasion of PEM and DIE.

Results

The main distribution of PEM and DIE was located in the posterior pelvic cavity (p < .001). The histopathological characteristics of different PEM forms were different: the contents of endometrioid glands, endometrioid stroma, smooth muscle, fibrous tissue and blood vessels in different lesions were statistically significant (all p < .050). Estrogen receptor (ER) of PEM and DIE was highly expressed in endometrioid glandular epithelium and endometrioid stroma, without statistical significance (p = .330/.113). Progesterone receptor (PR) was also highly expressed in endometrioid glandular epithelium and endometrioid stroma without statistical significance (p = .757/.798). Ki-67 expression of DIE in endometrioid glandular epithelium was significantly higher than that in brown and white lesions (p < .001), while its expression in the endometrioid stroma was not statistically significant in red lesions (p = .070), but higher than that in other PEM lesions (p < .001). Different morphological lesions had different invasiveness rates and depths of invasion to the peritoneum. White lesions had a deeper subperitoneal invasion level than transparent and vesicular lesions.

Conclusions

Although different morphological appearance of PEM is a degenerative process, some active brown lesions of PEM have invasive effects during the process and may further develop into DIE. PEM and DIE may be different developmental stages of the same disease.

KEY MESSAGES

• In summary, PEM is a progressive disease, and its different morphological appearance reflects different stages of lesion development.

• Ectopic endometrial cells have a destructive effect on the peritoneal structures; as the lesion progresses, it continuously infiltrates the subperitoneum.

• PEM and DIE are different development stages of the same disease. The homology of the two lesions has yet to be explored in terms of pathogenesis.

Keywords:

• Peritoneal endometriosis
• deep infiltrating endometriosis
• pathology

Acknowledgements

We would like to acknowledge the hard and dedicated work of all the staff that implemented the intervention and evaluation components of the study.

Author contributions

Conception and design of the research: MYQ and LH; acquisition of data: MYQ, RR, YRS, SQX and LH; analysis and interpretation of the data: YPW, MYQ and LH; statistical analysis: MYQ and LH; writing of the manuscript: MYQ; critical revision of the manuscript for intellectual content: LH; all authors read and approved the final draft.

Ethical approval

This study was conducted with approval from the Ethics Committee of Dalian Municipal Women and Children’s Medical Center (no. 2018040). This study was conducted in accordance with the Declaration of Helsinki.

Consent form

Written informed consent was obtained from all participants.

Disclosure statement

The authors declare that they have no competing interests.

Data availability statement

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. We declared that materials described in the manuscript, including all relevant raw data, will be freely available to any scientist wishing to use them for non-commercial purposes, without breaching participant confidentiality.

Additional information

Funding

Not applicable.