Distinguishing Erosive Lichen Planus From Differentiated Vulvar Intraepithelial Neoplasia

Interobserver Agreement Across Subspecialties for Diagnosis of Differentiated Vulvar Intraepithelial Neoplasia and Predictive Values of 20 Histologic Features

CONTEXT.—

Differentiated vulvar intraepithelial neoplasia (dVIN) is a human papillomavirus-independent lesion with the potential for rapid progression to invasive squamous cell carcinoma (SCC). The histopathologic features of dVIN are diverse, have overlapping characteristics with lichen sclerosus (LS) and lichen simplex chronicus (LSC), and may be diagnosed by dermatopathologists or gynecologic pathologists because of the vulva's anatomic location.

OBJECTIVES.—

To identify the salient histopathologic features of dVIN, particularly those that predict progression to SCC, and to evaluate interobserver agreement in diagnosing dVIN within the same subspecialty and across subspecialties.

DESIGN.—

One general surgical pathologist, 2 pathology-trained dermatopathologists, and 1 gynecologic pathologist blinded to the final diagnoses were asked to record 20 histopathologic features and to provide their final interpretations on cases of dVIN (n = 65), LS (n = 126), LSC (n = 112), and LS with LSC (n = 6).

RESULTS.—

Interobserver agreement for the 4 diagnoses and 10 histopathologic features was moderate. Logistic regression analysis indicated that keratin pearls, basal pleomorphism, and basal layer disarray were independent variables for diagnosing dVIN (coefficients 1.95, 1.97, and 0.91, respectively; P < .001) and progression to SCC (coefficients 1.96, 1.20, and 1.08, respectively; P < .001).

CONCLUSIONS.—

There is no single histopathologic feature pathognomonic for dVIN; however, the presence of keratin pearls, basal pleomorphism, and basal layer disarray should raise high suspicion for dVIN and concurrent SCC. Expertise in both dermatologic and gynecologic pathology is beneficial for diagnosing dVIN.

Clinicopathologic Diagnosis of Differentiated Vulvar Intraepithelial Neoplasia and Vulvar Aberrant Maturation

OBJECTIVE

The aim of the study was to describe the demographic, clinical, and histopathologic features of differentiated vulvar intraepithelial neoplasia (dVIN) and vulvar aberrant maturation (VAM).

METHODS

Specimens from 2010 to 2020 reported as dVIN or VAM were reviewed. Clinical data included age, rurality, symptoms, and evidence of lichen sclerosus (LS). Histopathologic data included epithelial thickness, keratinization, architectural and dyskeratotic features, stroma, p16, and p53. Differentiated vulvar intraepithelial neoplasia and VAM were distinguished by assessment of basal nuclear chromatin, enlargement, pleomorphism, and mitoses.

RESULTS

One hundred twenty women with a median age of 71 years had 179 examples of dVIN and VAM. Squamous cell carcinoma was concurrent in 66% and associated with rurality. Ten percent were asymptomatic, and all but 3 had evidence of LS. Differentiated vulvar intraepithelial neoplasia showed a range of thickness, architecture, and dyskeratosis; its unifying !feature was basal atypia. Differentiated vulvar intraepithelial neoplasia displayed hyperchromasia in 83% and easily observed mitoses in 70%. Nonkeratinizing morphology, subcategorized into basaloid and intermediate, occurred in 24% of women with dVIN. Traditional dVIN represented 62% of keratinizing cases; the remainder were atrophic (13%), hypertrophic (13%), acantholytic (8%), or subtle (5%). Vulvar aberrant maturation had abnormal stratum corneum, acanthosis, premature maturation, and enlarged vesicular nuclei. Null p53 helped distinguish dVIN from VAM and dermatoses.

CONCLUSIONS

The morphology of dVIN encompasses nonkeratinizing and keratinizing types, the latter subdivided into traditional, acantholytic, atrophic, hypertrophic, and subtle. Diagnosis relies on basal atypia with supportive p16 and p53. Atypia exists on a biologic spectrum with mild abnormalities of VAM and reactive change. Identification of dVIN and VAM requires collaboration between clinicians and pathologists experienced in vulvar disorders.

Anogenital High-Grade Squamous Intraepithelial Lesion Comorbid With Vulvar Lichen Sclerosus and Lichen Planus

OBJECTIVE

The aim of the study was to describe the clinicopathologic features of vulvovaginal or anal high-grade squamous intraepithelial lesion (HSIL) comorbid with lichen sclerosus and/or lichen planus (LS/LP).

METHODS

The local pathology database identified 37 consecutive cases from 2007 to 2019 of vulvar, vaginal, or anal HSIL among women who had a histopathologic diagnosis of vulvar LS/LP. Cases had p16 and p53 immunoperoxidase stains. Clinical data included age, relative location of HSIL and LS/LP, immune-modifying conditions, tobacco use, treatment type, and follow-up. Histopathologic data included HSIL morphology categorized as warty-basaloid or keratinizing, p16 and p53 patterns within HSIL, and features of LS/LP.

RESULTS

The mean age was 69 years with a median follow-up up 42 months. Lichen sclerosus, alone or in combination with LP, was the comorbid dermatosis in 89%. Lichen sclerosus/lichen planus was overlapping or adjacent to HSIL in two-thirds of cases and located separately in the remainder. Rates of tobacco use and immunologic dysfunction were each 40%. In cases of co-located LS and HSIL, sclerosis was absent under the neoplasia in 57%. Twenty-four percent of HSIL cases showed keratinizing morphology; block-positive p16 and suprabasilar-dominant p53 helped distinguish HSIL from human papillomavirus-independent neoplasia.

CONCLUSIONS

Histopathologic identification of comorbid HSIL and LS/LP may be challenging because of keratinizing morphology and loss of diagnostic features of LS. Clinicopathologic correlation and use of p16 and p53 are essential to achieve an accurate diagnosis and enact disease-specific management plans.

Clinicopathologic Diagnostic Criteria for Vulvar Lichen Planus

OBJECTIVE

The aim of the study was to describe the clinical and histopathologic features required for a clinicopathologic diagnosis of vulvar lichen planus (LP), which is divided into 3 types: erosive, classic, and hypertrophic.

MATERIALS AND METHODS

The International Society of the Study of Vulvovaginal Diseases tasked the Difficult Pathologic Diagnoses committee with development of a consensus document for the clinicopathologic diagnosis of vulvar LP, lichen sclerosus, and differentiated vulvar intraepithelial neoplasia. The LP subgroup reviewed the literature and formulated diagnostic criteria, then approved by the International Society of the Study of Vulvovaginal Diseases membership.

RESULTS

The clinicopathologic diagnosis of erosive LP incorporates 5 criteria: (a) a well-demarcated, glazed red macule or patch at labia minora, vestibule, and/or vagina, (b) disease affects hairless skin, mucocutaneous junction, and/or nonkeratinized squamous epithelium, (c) evidence of basal layer damage, categorized as degenerative or regenerative, (d) a closely applied band-like lymphocytic infiltrate, and (e) absent subepithelial sclerosis. The clinicopathologic diagnoses of classic and hypertrophic LP each require a characteristic clinical appearance accompanied by hyperkeratosis, hypergranulosis, acanthosis, basal layer degeneration, a closely applied lymphocytic infiltrate, and absent dermal sclerosis, with hypertrophic LP showing marked epithelial abnormality compared with classic LP.

CONCLUSIONS

Clinicopathological correlation yields the most reliable diagnosis of vulvar LP. Disease appearance overlaps with other physiologic, dermatologic, infectious, and neoplastic entities; a low threshold for biopsy at all morphologically distinct areas is recommended. Use of the histopathologic criteria described in this document may reduce the nondiagnostic biopsy rate for clinically diagnosed LP.

Erosive Vulvar Lichen Planus and Risk of Vulvar Neoplasia

OBJECTIVE

The aim of the study was to assess the risk of vulvar cancer and precursors in a cohort of women with vulvar lichen planus (LP) and the clinical and therapeutic features of these patients.

MATERIALS AND METHODS

A retrospective cohort study, including all the women with the diagnosis of vulvar LP, followed in one institution during a period of 11 years, was performed. Demographic and clinical data, as well as treatment, follow-up, and histology results, were evaluated.

RESULTS

A total of 127 women were diagnosed with vulvar LP. The mean follow-up time was 3.9 ± 0.5 years (range = 1-11 years). Ultrapotent topical corticosteroids were first-line treatment in 91.8% (n = 112), with 32 cases (25.2%) needing an alternative treatment. Overall, 30 biopsies were performed in 19 women (15%). Vulvar high-grade squamous intraepithelial lesion was diagnosed in 3 women (2.4%), 2 (1.6%) of whom were later diagnosed with vulvar squamous cell carcinoma. No cases of differentiated vulvar intraepithelial neoplasia were observed.

CONCLUSIONS

Premalignant/malignant transformation in women with vulvar LP under surveillance and compliant with treatment is low. A close follow-up seems to be crucial to prevent future malignancy. Biopsies should be performed whenever a suspicious lesion seems during follow-up.

Diagnostic Criteria for Differentiated Vulvar Intraepithelial Neoplasia and Vulvar Aberrant Maturation

OBJECTIVE

The aim of the study was to describe the features required for diagnosis of differentiated vulvar intraepithelial neoplasia (dVIN) and vulvar aberrant maturation (VAM).

MATERIALS AND METHODS

The International Society of the Study of Vulvovaginal Diseases tasked the difficult pathologic diagnoses committee to develop consensus recommendations for clinicopathologic diagnosis of vulvar lichen planus, lichen sclerosus, and dVIN. The dVIN subgroup reviewed the literature and formulated diagnostic criteria that were reviewed by the committee and then approved by the International Society of the Study of Vulvovaginal Diseases membership.

RESULTS

Differentiated vulvar intraepithelial neoplasia is the immediate precursor of human papillomavirus (HPV)-independent vulvar squamous cell carcinoma and shows a spectrum of clinical and microscopic appearances, some overlapping with HPV-related neoplasia. The histopathologic definition of dVIN is basal atypia combined with negative or nonblock-positive p16 and basal overexpressed, aberrant negative, or wild-type p53. The most common pattern of dVIN is keratinizing with acanthosis, aberrant rete ridge pattern, and premature maturation. The morphologic spectrum of keratinizing dVIN includes hypertrophic, atrophic, acantholytic, and subtle forms. A few dVIN cases are nonkeratinizing, with basaloid cells replacing more than 60% of epithelium. Vulvar aberrant maturation is an umbrella term for lesions with aberrant maturation that arise out of lichenoid dermatitis and lack the basal atypia required for dVIN.

CONCLUSIONS

Evaluation of women at risk for dVIN and VAM requires a collaborative approach by clinicians and pathologists experienced in vulvar disorders. Close surveillance of women with lichen sclerosus and use of these recommendations may assist in prevention of HPV-independent squamous cell carcinoma through detection and treatment of dVIN and VAM.

Comparison of p53 immunohistochemical staining in differentiated vulvar intraepithelial neoplasia (dVIN) with that in inflammatory dermatoses and benign squamous lesions in the vulva

AIMS

Differentiated vulvar intraepithelial neoplasia (dVIN), the precursor lesion to human papillomavirus-independent vulvar squamous cell carcinoma (VSCC), can be difficult to distinguish from vulvar inflammatory dermatoses. Our goal was to determine if p53 could be a useful biomarker for dVIN, by characterizing p53 percentage, intensity and patterns of staining in dVIN and its histological mimics.

METHODS AND RESULTS

We studied p53 immunohistochemical staining patterns in 16 dVIN cases and 46 vulvar non-neoplastic squamous lesions [12 lichen sclerosus (LS); seven lichen simplex chronicus; three lichen planus (LP); six psoriasis; 13 spongiotic dermatitis (SPO); and five candidiasis]. dVIN cases were adjacent to a p16-negative invasive VSCC in resection specimens. All dVIN cases showed null-type or moderate to strong uniform p53 staining in >70% of basal cells, with moderate to strong continuous parabasal staining extending to two-thirds of the epidermis. This was in contrast to weak or weak to moderate patchy p53 staining in the majority of other lesions. Moderate to strong and increased basal p53 staining (≥70%) was also observed in a subset of LS cases (5/12, 42%), LP cases (1/3, 33%), and SPO cases (36%, 4/11); however, in all categories, this was limited to the basal layer, and any staining in the parabasal layers was patchy.

CONCLUSION

Strong and uniform p53 staining of basal cells, extending into the parabasal layers, and a complete absence of staining (null type) is useful in distinguishing dVIN from other mimics in the vulva. p53 staining of lesser intensity or quantity, particularly basal overexpression only, overlaps with that in vulvar inflammatory lesions.

Classic and Hypertrophic Vulvar Lichen Planus

OBJECTIVES

Three types of lichen planus (LP) occur on the vulva: erosive, classic, and hypertrophic. The latter 2 occur on keratinized skin and little is known about their clinicopathologic appearance.

MATERIALS AND METHODS

Vulvar biopsies of keratinized skin reported as LP or "lichenoid" between 2011 and 2017 were reviewed. Inclusion required age of older than 18 years, a lichenoid tissue reaction, and insufficient abnormal dermal collagen to diagnose lichen sclerosus. Clinical and histopathologic data were collected and cases were categorized as hypertrophic, classic, or nonspecific lichenoid dermatosis. Descriptive statistics were performed and groups were compared with the Fisher exact test.

RESULTS

Sixty-three cases met criteria for inclusion. Twenty-nine (46%) cases were categorized as hypertrophic LP, 21 (33%) as classic LP, and 13 (21%) as nonspecific lichenoid dermatosis. There were no significant differences in age, primary symptom, biopsy location, or duration of disease between the 3 groups. When compared with classic and nonspecific disease, hypertrophic LP was less likely to have comorbid dermatoses and more likely to be red, diffuse, have scale crust, and contain plasma cells in the infiltrate. Nonspecific disease had similar clinical features to classic LP but was less likely than the other 2 categories to have a dense lymphocytic infiltrate and exocytosis.

CONCLUSIONS

Vulvar LP on keratinized skin has a diversity of appearances and presents a clinicopathologic challenge. Further research is required to understand the natural history of hypertrophic LP and the underlying diagnosis of nonspecific lichenoid cases.

Is Vulvovaginal Lichen Planus Associated With Squamous Cell Carcinoma?

Objective

The aim of the study was to assess for the presence of vulvar lichen planus (LP) in association with human papillomavirus (HPV)–independent squamous cell carcinoma (SCC).

Materials and Methods

We performed a clinicohistopathologic review of consecutive vulvectomies and wide local excisions for HPV-independent vulvar or vaginal SCC from 2007 to 2017. Data collected included site of SCC, adjacent precursor lesions and dermatoses, dermatologic treatment, and outcome.

Results

There were 43 cases of primary HPV-independent vulvar SCC treated by excision, but no vaginal cancers. Eighteen women (42%) had a preoperative diagnosis of lichen sclerosus (LS); none had a diagnosis of LP. Topical corticosteroids were prescribed in 19 (44%) of 43, with 4 women placed on maintenance therapy. Tumors arose from the labia minora, labia majora, and periclitoris, but not from vestibule or perianus. On histopathological review, LS was present in 41 (95%) of 43 specimens, 1 had a nonspecific lichenoid reaction, and 1 had lichen simplex; both of the latter had subsequent biopsies showing LS. Lichen planus was not seen in association with SCC. Differentiated vulvar intraepithelial neoplasia (dVIN) was present in 38 (88%) of 43 specimens, whereas 1 had acanthosis with altered differentiation and 4 (9%) had no precursor lesion. Differentiated vulvar intraepithelial neoplasia had standard, basaloid, and hypertrophic morphology, superficially resembling erosive LP in 9 (24%) of 38 and hypertrophic LP in 6 (16%) of 38.

Conclusions

Lichen planus was not seen in association with HPV-independent vulvar SCC, whereas LS was underrecognized and inadequately treated in this group. Pathologists should be aware that dVIN may superficially resemble erosive or hypertrophic LP.

Lichenoid Dermatitis of the Vulva: Diagnosis and Differential Diagnosis for the Gynecologic Pathologist

Inflammatory processes affecting the vulva may present a unique challenge due to location specific changes. Different factors are behind the intricacy in the presentation of vulvar dermatoses. First, the vulva is lined by different epithelia (hair-bearing keratinized epithelium, modified mucosa, and mucosa). Furthermore, among other factors, this organ is exposed to friction, occlusion, and trauma. Lastly, as there is a tendency to look for health care advice at an advanced stage of the disease, the lesion may be modified by secondary changes due to self-treatment. This article describes the clinical presentation and pathologic features of vulvar dermatoses with a lichenoid pattern and highlights practical points for their diagnoses.