(187) Routine Staining of Excised Vestibular Specimens with Hematoxylin and Eosin and Immunohistochemical Staining with CD117 and PGP9.5: Added Value to Patients

Abstract

Abstract Introduction Neuroproliferative vestibulodynia (NPV) is associated with increased density of mast cells in the epithelial basement membrane and nerve endings in the sub-epithelial stroma. As cellular pathology cannot be visualized on physical examination, diagnosis is difficult, and often delayed. Patients with entrance dyspareunia are suspected to have NPV only after excluding other forms of vestibulodynia. Surgical specimens from complete vestibulectomy with vaginal advancement flap reconstruction are sent to pathology for routine staining with hematoxylin and eosin (H&E). Since 2019 we have also ordered immunohistochemical staining with CD117 and PGP9. Objective We wished to compare the pathologic findings in excised vestibular specimen examined by routine H&E staining versus by CD117 and PGP9.5, and to assess the significance to the patient of having both pathologic examinations performed. Methods Patients with suspected neuroproliferative vestibulodynia who underwent complete vestibulectomy with vaginal advancement flap reconstruction had both routine H&E staining and CD117/PGP9.5 staining of the excised specimen. Patients were asked post-operatively if and how this information benefitted them. Results Fifty-six patients formed the study group. Based on H&E staining, all patients were diagnosed with benign squamous vestibular epithelium with chronic inflammation. Gross examination showed tissue sizes varying from 5-11 cm long x 0.5 – 4 cm wide x 0.1 – 0.7 cm thick. Microscopic examination showed chronic inflammatory infiltrate at the superficial sub-epithelial stroma (Fig 1). This was composed of mature appearing lymphocytes in 87%, and a mixture of lymphocytes and plasma cells in 13%. Eosinophils were noted in 25% cases. P16 immunohistochemical staining, performed to rule out HPV when appropriate, was negative in all cases. Focal parakeratosis was noted in 7% cases. No ulcers, dysplastic or malignant cells were noted in any specimen. Based on CD117 and PGP9.5 staining, the diagnosis of NPV was established (Figs 2, 3). Positive results consistent with excess mast cells, greater than 8 cells per high power field x400, were noted in 100% of cases. All patients (100%) valued the pathologic information, especially regarding the positive CD117 and PGP9.5 staining as final confirmation of their NPV diagnosis, in particular after experiencing medical gaslighting. They consistently used the term “validating”, providing “tangible evidence” of a “physical problem wrong with me” when they had been told their “pain didn’t exist”. “Having that ‘knowledge’ was priceless. It's one thing to have a belief that I had neuroproliferative vestibulodynia. It's another thing to KNOW. To have that indisputable proof is one of the most gratifying and emotional moments in my healing journey. It shows that there was something wrong. It wasn't all in my head. I didn't need to ‘just relax’.” Conclusions The clinical diagnosis of NPV is based on excluding other forms of vestibulodynia. The pathologic diagnosis of NPV is not based on routine pathology staining but on immunohistochemical staining with CD117 and PGP9.5. If a patient is ignored, misdiagnosed, or invalidated by a provider, the patient loses self-confidence and faith in their own abilities. Providing pathologic evidence of the root cause of entrance dyspareunia plays a significant role in the healing process. Disclosure No