(004) ROUTINE PATHOLOGY EXAMINATION OF EXCISED SPECIMEN FROM PATIENTS WITH NEUROPROLIFERATIVE VESTIBULODYNIA
Authors: Goldstein I , Kim N N , Goldstein S W , Drian A , Yee A 
Published: June 2024

Abstract

Introduction
Neuroproliferative vestibulodynia (NPV) is suspected in individuals with vulvas with complaints of entrance dyspareunia, vestibular allodynia and hyperalgesia, after ruling out other causes. When conservative biopsychosocial treatments for suspected NPV are unsuccessful, vestibulectomy may be an appropriate option. Excised vestibular surgical specimens are routinely sent for pathologic assessment including hematoxylin and eosin (H&E) staining.

Objective
To review reports of gross and microscopic pathology examinations of excised vestibular specimens from a cohort of patients with NPV and compare immunohistochemical staining density among subgroups classified by severity of subepithelial inflammatory infiltrate.

Methods
Excised specimens from vestibulectomy surgeries were placed in 10% neutral buffered formalin prior to pathology examination. Routine pathology assessment included gross examination and cytological characterization of H&E-stained vestibular tissue for malignancy, viral nuclear changes (in addition to P16 staining as needed), and quality of the vestibular epithelium and subepithelial inflammatory infiltrate. Severity of this infiltrate was classified by the pathologist as mild, mild-moderate, moderate, or severe. Additional vestibular tissue sections were processed for immunohistochemical staining for CD117 and PGP9.5, protein markers consistent with mast cells and nerves, respectively. Separating the tissues into subgroups based on severity of subepithelial inflammatory infiltrate, they were compared to mast cell counts and immunopositive mean fractional area for CD117 and PGP9.5 using the Kruskal-Wallis test.

Results
Gross examinations of the 1:00-11:00 (n = 63) and 12:00 (n = 54) regions of vestibular tissue showed mean dimensions (length, width, thickness) to be 5.8 x 2.1 x 0.6 cm and 1.0 x 0.7 x 0.3 cm, respectively. Microscopic examinations revealed no malignant cells in any specimen, and viral nuclear findings were consistent with HPV in 3 specimens. Vestibular tissue was characterized as non-reactive squamous epithelium in 91% and 93% of specimens for the 1:00-11:00 and 12:00 regions, respectively. Mature lymphocytes were found in the subepithelial stromal infiltrate of 67% of specimens in both the 1:00-11:00 and 12:00 regions. Severity of subepithelial stromal infiltrate was reported as: mild in 67% and 65%; mild-moderate in 5% and 4%; moderate in 14% and 15%; and severe in 14% and 17% of cases for the 1:00-11:00 and 12:00 regions, respectively. Among the subgroups categorized by severity of inflammatory infiltrate, there were no significant differences for CD117-immunopositive cell counts or mean fractional area of CD117 and PGP9.5 in the 1:00-11:00 and 12:00 regions.

Conclusions
Routine pathology examination including H&E staining is standard for vestibulectomy specimens. There were no significant differences found among subgroups comparing severity of subepithelial inflammatory infiltrate with immunohistochemical data. Thus, information gleaned from routine pathology examination did not provide confirmation of the diagnosis of NPV. To better understand NPV, excised vestibular tissue should also be immunostained for CD117 and PGP9.5.

Disclosure
No.