p16 Expression and Biological Behavior of Flat Vulvar Low-grade Squamous Intraepithelial Lesions (LSIL)

High-grade vulvar intraepithelial neoplasia: comprehensive characterization and long-term vulvar carcinoma risk

AIMS

Adequate diagnosis of human papillomavirus (HPV)-associated high-grade squamous intraepithelial lesion (HSIL) and HPV-independent vulvar intraepithelial neoplasia (VIN) is essential but can be challenging. We comprehensively characterized a large population-based series of vulvar lesions, originally reported as high-grade VIN, and assessed the cancer risk.

METHODS AND RESULTS

Baseline high-grade VIN of 751 patients were categorized by histopathological reassessment, integrating the results of immunohistochemistry (p16INK4a , p53, Ki-67) and HPV DNA testing. Integrated analyses resulted in 88.4% HPV-associated lesions (77.0% HSIL, 10.9% low-grade SIL [LSIL], and 0.4% vulvar squamous cell carcinoma [VSCC]), 10.9% HPV-independent lesions (6.1% HPV-independent VIN, 4.7% nondysplastic lesions, and 0.1% VSCC) and 1.1% inconclusive lesions. HSIL demonstrated p16INK4a block-positivity in 99.0%, increased Ki-67 in ≥2/3rd of the epithelium in 93.6%, and HPV positivity in 99.6%. In HSIL, a p53 wildtype mid-epithelial staining pattern was common (51.6%) while this was not observed in HPV-independent lesions. HPV-independent VIN harboured mutant p53 patterns in 65.2% and showed a wide morphological spectrum, ranging from differentiated to nondifferentiated ('HPV-associated-like', in 41.3%). Kaplan-Meier analyses showed a 10-year cancer risk of 8.0% in HPV-associated HSIL, 67.4% in HPV-independent VIN/p53mutant, and 27.8% in HPV-independent VIN/p53wildtype. Strikingly, the 10-year cancer risk was 73.3% in HPV-independent VIN with nondifferentiated ('HPV-associated-like') morphology.

CONCLUSION

Immunohistochemistry by p16INK4a and p53 is highly recommended for optimal categorization into HPV-associated and HPV-independent VIN, which is of utmost importance given the different cancer risk. The high cancer risk of HPV-independent VIN underscores the need for surgical treatment and close follow-up, especially in case of a p53 mutant pattern and/or nondifferentiated morphology.

Squamous and Glandular Lesions of the Vulva and Vagina: What's New and What Remains Unanswered?

A number of changes have been introduced into the 5th Edition of the World Health Organization (WHO) Classification of squamous and glandular neoplasms of the vulva and vagina. This review highlights the major shifts in tumor classification, new entities that have been introduced, recommendations for p16 immunohistochemical testing, biomarker use, molecular findings and practical points for pathologists which will affect clinical care. It also touches upon several issues that still remain answered in these rare but undeniably important women's cancers.

The histopathological results of vestibulectomy specimens in localized provoked vulvodynia in Turkey

Introduction

Localized Provoked Vulvodynia (LPV) is a gynecological disease that is difficult to manage. Despite the wide spectrum of pathophysiological mechanisms and treatment modalities, there is limited success in the management of this disease. Surgical treatment is usually performed as the last resort. We aimed to investigate the histopathological results of 38 women with LPV who underwent surgical vestibulectomy.

Methods

of the 55 women that were diagnosed with LPV and underwent vulvar vestibulectomy, 38 patients with complete histopathological results were included in this retrospective study.

Results

in 14 patients, the pathological reports revealed Low-Grade Squamous Intraepithelial Lesions (LGSIL) (36.8%) whereas for 21 cases (55.2%), the findings were concordant with vestibulitis. The remaining three patients (7.8%) were diagnosed with lichen simplex chronicus.

Conclusion

the presence of LGSIL in the surgical specimens of LPV cases is noteworthy. In this group of patients, surgical excision may contribute to the prevention of progression into high-grade lesions. The relationship between Human Papilloma Virus (HPV) infections and LPV should be further investigated.