Obstet Gynecol Sci.  2021 Sep;64(5):454-461. 10.5468/ogs.21114.

Detection of nerve fibers in the eutopic endometrium of women with endometriosis, uterine fibroids and adenomyosis

• Yadav G
• Rao M
• Gothwal M
• Singh P
• Kathuria P
• Sharma PP

• KMID: 2520265
• DOI: http://doi.org/10.5468/ogs.21114

Abstract

Objective
The primary objective of this study was to establish the presence of nerve fibers in the eutopic endometrium of women with endometriosis and to determine whether these nerve fibers are exclusive to endometriosis or are also found in other pelvic pathologies associated with dysmenorrhea.
Methods
Endometrial tissue was obtained by aspiration (Pipelle), endometrial curettage, or following hysterectomy in women with endometriosis confirmed through histopathological examination, leiomyomas, and adenomyosis. The eutopic endometrium was subjected to immunohistochemical staining to detect PGP 9.5, which is a highly specific pan-neuronal marker. The nerve fiber density was correlated with the patient’s pain score, as indicated by the Visual Analog Scale. A control group was formed by staining the endometrium of women presenting with dysmenorrhea but without the above-mentioned disorders.
Results
Nerve fibers were observed in sections of the endo-myometrium (in the deep endometrium) in 68% of patients with endometriosis who underwent hysterectomy or a deep endometrial biopsy. Nerve fibers were not observed in the aspirated endometrium of women with endometriosis. Only 13.7% of women with adenomyosis and 3.3% of women with fibroids had nerve fibers in their endometrium. Nerve fiber density was correlated with pain score in women with endometriosis.
Conclusion
Nerve fibers were found in the functional layer of eutopic endometrium in women with endometriosis; hence, we concluded that the presence of nerve fibers in the eutopic endometrium could diagnose endometriosis with a fairly good specificity of 92.7%. However, the absence of nerve fibers does not always exclude the disease.

Keyword

Adenomyosis; Dysmenorrhea; Endometriosis; Leiomyoma; Nerve fibers

Figure

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  Fig. 1 Patient flow following recruitment in the study. HPR, histopathological report; EB, endometrial biopsy.

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  Fig. 2 The endometrium shows nerve fibers highlighted by the protein gene product (PGP) 9.5 antibody (black arrow) and endometrial gland (red asterisks) in a case of endometriosis (immunohistochemical staining, ×40).

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  Fig. 3 High power view (immunohistochemical staining, ×40) of a proliferative endometrium (red asterisk) showing nerve fibers highlighted by the protein gene product (PGP) 9.5 antibody (black arrow) in a case of endometriosis.

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  Fig. 4 (A) The endometrium shows nerve fibers highlighted by the protein gene product (PGP) 9.5 antibody (black arrows) in a case of adenomyosis. (B) High power view of the image in (A) where the upper right corner shows the myometrium (red asterisks) (immunohistochemical staining, ×40).

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  Fig. 5 Correlation of the Visual Analog Scale (VAS) score and nerve fiber density among patients with endometriosis.

Reference

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