Nonsclerotic Lichen Sclerosus: Definition of a Concept and Pathologic Description.

OBJECTIVE: Nonsclerotic lichen sclerosus (NSLS) refers to the clinicopathologic situation of examination findings consistent with lichen sclerosus (LS) but without dermal sclerosis on microscopy. This review aims to describe the features of NSLS and provide a classification framework. METHODS: The International Society of the Study of Vulvovaginal Diseases tasked the Difficult Pathologic Diagnoses Committee with development of consensus documents for conditions with problematic histopathology. The Difficult Pathologic Diagnoses Committee reviewed the literature on NSLS and formulated descriptions and diagnostic criteria, then approved by the International Society of the Study of Vulvovaginal Diseases membership. RESULTS: Nonsclerotic LS may be categorized into 4 histopathologic subtypes: lichenoid dermatitis, hypertrophic lichenoid dermatitis, dermal fibrosis without acanthosis, and dermal fibrosis with acanthosis. Each has a pathologic differential diagnosis of 1 or more entities, so clinical correlation is required for final diagnosis of LS. There is no evidence to support a reliable association between absent sclerosis and clinical appearance, duration, or oncogenic potential of LS. CONCLUSIONS: Pathologists and clinicians should be familiar with the concept of NSLS and its implications for patient management. Use of the term "early LS" to indicate a lack of sclerosis in presumed LS should be abandoned. Clinical correlation is required to confirm LS from among the differential diagnoses.

Mass Spectrometry Proteomic Analysis of Four p53 Patterns in Differentiated Vulvar Intraepithelial Neoplasia.

OBJECTIVE: The histopathologic diagnostic criteria of differentiated vulvar intraepithelial neoplasia (dVIN), the precursor of human papillomavirus-independent squamous cell carcinoma, are basal atypia, a negative or non-block-positive p16, and a supportive p53 immunohistochemistry (IHC). Several different patterns of supportive p53 IHC have been described. This study aims to determine the relationship between p53 IHC patterns and mass spectrometry analysis of cellular proteins in dVIN. METHODS: Four patterns of p53 IHC were studied: overexpression, cytoplasmic, wild type, and intermediate expression between wild type and overexpression. For each pattern, tissue samples of 4 examples were subjected to mass spectrometry. RESULTS: The protein profile within each p53 IHC pattern shared common features. Each of the 4 p53 patterns had a distinguishable protein profile when compared with the other 3 patterns. CONCLUSIONS: The distinguishable protein profiles in different p53 IHC patterns suggest diverse mechanisms of TP53 dysfunction. Subtyping dVIN by p53 IHC is worthy of further study because varied protein expression profiles may translate into different clinical behavior.

The Clinicopathologic Challenge of Nonneoplastic Vulvar Acanthosis.

OBJECTIVE: The aim of the study was to evaluate clinicopathologic features of cases demonstrating an acanthotic tissue reaction not clearly consistent with psoriasis, lichen simplex chronicus, mycosis, or condyloma. MATERIALS AND METHODS: This is a retrospective pathologic case series of biopsies reported as "benign acanthotic lesion" and "acanthotic tissue reaction" that lacked a clear diagnosis on expert review. Cases with nuclear atypia were excluded. Clinical and histopathologic data were collected, immunohistochemistry for p16 and p53 were obtained, and molecular testing for 28 common anogenital human papillomavirus (HPV) genotypes was undertaken. RESULTS: There were 17 cases with a median age of 47 years. Unilaterality and medial location were clinical reasons for diagnostic difficulty. Histopathologic uncertainty often related to lack of papillary dermal fibrosis to support lichen simplex chronicus or psoriasiform lesions without parakeratosis, subcorneal pustules, and/or mycotic elements. Firm pathologic diagnoses were not possible, but 3 groups emerged: favoring chronic dermatitis, favoring psoriasis, and unusual morphologies. p16 results were negative or nonblock positive while p53 was normal or basal overexpressed. Human papillomavirus testing was negative in 12, low positive for HPV 16 in 1, unassessable in 3, and not requested in 1. CONCLUSIONS: There is a group of acanthotic tissue reactions that cannot be classified with standard histopathologic assessment. Further clinicopathologic research into unilateral acanthotic lesions may provide insight into separation of psoriasis and mycosis when organisms are absent. Once nuclear atypia is excluded, immunohistochemistry for p16 and p53 and HPV molecular testing do not assist in diagnostic identification.

Desquamative Inflammatory Vaginitis and Plasma Cell Vulvitis Represent a Spectrum of Hemorrhagic Vestibulovaginitis.

OBJECTIVE: The aim of the study was to identify whether desquamative inflammatory vaginitis (DIV) and plasma cell vulvitis (PCV) are distinct clinicopathologic entities. MATERIALS AND METHODS: The pathology database identified biopsies described as "vaginitis" or "vulvitis" occurring in nonkeratinized epithelium or mucocutaneous junction. Exclusions were age less than 18 years, unavailable slides or records, concurrent neoplasia, or histopathology consistent with other entities. Clinical data included demographics, symptoms, examination, microbiology, treatment, and response. Histopathologic review documented site, epithelial thickness and characteristics, infiltrate, and vascular abnormalities. Cases were analyzed according to histopathologic impression of DIV or PCV based on previous pathologic descriptions. RESULTS: There were 36 specimens classified as DIV and 18 as PCV from 51 women with mean age of 51 years; 3 (6%) had concurrent biopsies with both. Pain was more common in PCV, but rates of discharge, itch, and bleeding were comparable. Rates of petechiae or erythema were similar and vaginal examination was abnormal in 72% of PCV cases. All DIV and 33% of PCV occurred in squamous mucosa; the remaining PCV cases were from mucocutaneous junction. Mean epithelial thickness, rete ridge appearance, exocytosis, and spongiosis were similar in DIV and PCV. Epithelial erosion, wide-diameter lesions, plasma cells, and stromal hemosiderin occurred in both but were more common in PCV. Lymphocyte-obscured basal layer, narrow-diameter lesions, hemorrhage, and vascular congestion were seen in both, but more common and marked in DIV. CONCLUSIONS: Desquamative inflammatory vaginitis and PCV have overlapping symptoms, signs, and histopathologic features. They may represent a single condition of hemorrhagic vestibulovaginitis with varying manifestations according to location and severity.

Colposcopic outcomes for symptomatic patients with a negative oncogenic human papillomavirus test.

This study assesses outcomes of colposcopy referrals for post-coital, intermenstrual, or other abnormal bleeding with negative oncogenic human papillomavirus and negative to low-grade cytology. Of 112 cases with median age of 34.5 years, cervical biopsy occurred in 19%, treatment of ectropion in 19%, endometrial sampling in 8%, polypectomy in 4%, and contraceptive change in 2%. No cervical or endometrial neoplasia was detected. Patients with bleeding symptoms and reassuring co-test may instead attend a general gynaecology clinic.

Erosive Lichen Sclerosus-A Clinicopathologic Subtype.

OBJECTIVE: The aim of the study was to identify whether erosive lichen sclerosus (LS) is a distinct clinicopathologic subtype. MATERIALS AND METHODS: The pathology database was searched for "erosion," "erosive," "ulcer," and "lichen sclerosus." Inclusion criteria were histopathologic diagnosis of LS and erosion or ulcer overlying a band of hyalinization and/or fibrosis. Exclusions were concurrent neoplasia and insufficient tissue. Histopathologic review documented site, epithelial thickness, adjacent epidermal characteristics, infiltrate, and dermal collagen abnormality. Clinical data included demographics, comorbidities, examination findings, microbiologic results, treatment, and response. RESULTS: Ten examples of erosive LS and 15 of ulcerated LS occurred in 24 women with a mean age of 67 years. Ulcerated LS was associated with diabetes and nontreatment at time of biopsy. Clinicians identified red patches in all but 1 case of erosive LS. Ulcerated LS was documented as fissure, ulcer, or white plaque, with 8 (53%) described as lichenified LS with epidermal breaches. Erosive LS favored hairless skin with normal adjacent stratum corneum sloping gently into erosion, whereas most ulcers in LS had an abrupt slope from hair-bearing skin. All cases were treated with topical steroids; 2 patients with erosive LS and 10 with ulcerated LS also had oral antifungals, topical estrogen, antibiotics, and/or lesional excision. Treatment yielded complete resolution in 50%. CONCLUSIONS: Erosive LS is an unusual clinicopathologic subtype characterized by red patches on hairless skin seen microscopically as eroded epithelium overlying a band of hyalinized or fibrotic collagen. In contrast, ulcerated LS is usually a traumatic secondary effect in an uncontrolled dermatosis.

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.

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.

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.

Interpretation of Nondiagnostic Vulvar Biopsies.

OBJECTIVE: The aim of the study was to assess clinical and histopathologic characteristics of symptomatic women who underwent a nondiagnostic biopsy of the inner vulva. MATERIALS AND METHODS: Consecutive nondiagnostic biopsies from medial labia minora, posterior fourchette, and vestibule obtained from symptomatic women between 2011 and 2015 were reviewed for this retrospective histopathologic case series. Histopathologic assessment included site, basal layer appearance, lymphocytic infiltrate, and presence of fibrosis or sclerosis. Examination findings, treatment, initial impression, and final clinical diagnosis were recorded. Descriptive statistics were performed; clinical and histopathologic characteristics were compared with Fisher exact test. RESULTS: There were 85 cases; mean age was 53 years. Most women presented with painful erythema and underwent biopsy to confirm (30, 35%) or exclude (43, 51%) lichen planus. After clinical follow-up and histopathologic review, most cases had persistent diagnostic discordance. Final clinical diagnoses were available in 70 women: lichen planus in 27 (38%), vulvodynia in 15 (21%), and the other 28 (40%) had LS (8), plasma cell vulvitis (5), psoriasis (4), dermatitis (4), candidosis (3), estrogen deficiency (3), and aphthosis (1). Histopathologic review highlighted the difficulty in distinguishing mucosa-associated lymphoid tissue from an inflammatory infiltrate in 23 (27%) of cases. Compared with other sites, biopsies from the mucocutaneous junction were more likely to be associated with a positive culture for Candida albicans. CONCLUSIONS: Nondiagnostic biopsies from the inner vulva should prompt thoughtful multidisciplinary review, but more research is required to resolve the problem of clinicopathologic discordance through better understanding of vulvar histology and pathophysiology.

Vestibulovaginal Sclerosis Versus Lichen Sclerosus.

To determine if vestibulovaginal sclerosis and lichen sclerosus (LS) are 2 distinct entities. Biopsies obtained from the vagina or vulvar vestibule that contained abnormal subepithelial collagen were reviewed. Cases were categorized either as LS or vestibulovaginal sclerosis based on presence or absence of basal layer degeneration and lymphocytic infiltrate. Clinical data collected included examination findings, biopsy site and indication, previous vulvovaginal surgery, medications at time of biopsy, vulvar LS, treatment, and response. There were 15 cases with a mean age of 62 yr (range: 32-86 yr); 12 (80%) specimens were from vestibule and 3 from vagina. Nine cases were categorized as LS because of lymphocytic infiltrate in combination with basal layer degeneration, of these 8 had LS elsewhere on vulvar skin. Six cases were classified as vestibulovaginal sclerosis and had an absent or sparse lymphocytic infiltrate and essentially normal epithelium; none of these had vulvar LS. While vestibulovaginal sclerosis and lichen sclerosus are distinguishable clinically and histopathologically, further studies are needed to determine if vestibulovaginal sclerosis is a subset of LS or a different condition.

Comorbid Vulvar Lichen Planus and Lichen Sclerosus.

OBJECTIVES: The aims of the study are to assess the histopathologic characteristics of vulvar biopsies consistent with lichen planus (LP) in women with a previous or concurrent histopathologic diagnosis of vulvar lichen sclerosus (LS) and to describe the clinical features of comorbid LP and LS. MATERIALS AND METHODS: Patients were included if a diagnosis of LP was confirmed after review of the hematoxylin and eosin slides and the histopathology reporting LS noted a band of abnormal collagen. Data were collected on anatomic site, clinical appearance, histopathology, microbiology, treatment, and follow-up. RESULTS: There were 31 cases with a mean age of 69.5 years. Thirty specimens showed erosive LP, of which 22 were from inner labium minus and 8 from vestibule. There were no significant differences between biopsy site in epithelial thickness, erosion, lymphocytic infiltrate, or basal layer pattern. One third of cases showed a regenerative pattern of LP. Of the 26 patients with clinical records available, erythema at the biopsy site was noted in all cases; in 23 the notes specified central erythema and peripheral pallor. Forty-six percent were prescribed topical corticosteroids before biopsy. All 26 were treated with topical corticosteroids, 23% were prescribed antimycotics, and 38% required other supplemental therapies. CONCLUSIONS: Comorbid vulvar LP and LS are not rare; clinicians suspecting one should evaluate for the other and consider separate biopsies of morphologically distinct areas. Clinicopathological correlation is an invaluable tool in assessing biopsies when both diagnoses are suspected, because the regenerative pattern of LP may otherwise be overlooked or misdiagnosed.

Can Routine Histopathology Distinguish Between Vulvar Cutaneous Candidosis and Dermatophytosis?

OBJECTIVES: This study aimed to determine if vulvar cutaneous candidosis and dermatophytosis can be distinguished by routine histopathology. MATERIALS AND METHODS: Twenty-four cases of periodic acid-Schiff-stained vulvar biopsies with a diagnosis of cutaneous mycosis were reviewed and histopathological characteristics on both periodic acid-Schiff and hematoxylin and eosin were recorded. Data were collected on age, clinical impression, microbiological results, and treatment, and all specimens underwent multiplex polymerase chain reaction analysis. RESULTS: The mean age was 60 years, and all but 3 women had at least 1 risk factor for mycosis including 15 (62.5%) with lichen sclerosus and/or planus managed with topical corticosteroids. A clinical suspicion of tinea or candidosis was documented in 12 (50%) of the cases. Vulvovaginal swabs showed Candida species in 9 women; one skin scraping was positive for Trichophyton rubrum. Microbiology was not obtained in 8 patients, 5 had a negative swab, and 1 had negative skin scrapings. No histopathological or morphological features distinguished Candida species from dermatophytes. Organisms appeared as basophilic structures in the stratum corneum in 15 (62.5%) hematoxylin and eosin-stained slides. Polymerase chain reaction results were positive for Candida species in 5 (21%) and for dermatophytes in 3 (13%), negative in 13, and unassessable in 3 cases. CONCLUSIONS: Vulvar cutaneous candidosis and dermatophytosis cannot be reliably distinguished by routine histopathology or specific polymerase chain reaction. A high index of suspicion combined with adequate microbiological testing remains the best approach to differentiating between the 2, which impacts on counseling, treatment, and prognosis.

Distinguishing Erosive Lichen Planus From Differentiated Vulvar Intraepithelial Neoplasia.

OBJECTIVE: Erosive lichen planus (LP) and differentiated vulvar intraepithelial neoplasia (dVIN) may display overlapping histopathologic features. MATERIALS AND METHODS: We searched the local pathology database for vulvar biopsies reported as dVIN or erosive vulvitis during 2011 to 2013 inclusive. After review of patient notes and slides, there were 5 cases with a clinical appearance and course consistent with erosive LP and histopathology showing epithelial regeneration. We then selected 5 cases of dVIN in which the clinical course and histopathology supported the diagnosis. We performed immunohistochemistry for p16 and p53 on all cases and did copy variant analysis on 1 case each of erosive LP and dVIN. RESULTS: Histopathology of the LP cases showed epithelial thinning, absent stratum corneum, lack of maturation, as well as nuclear changes of enlargement, pleomorphism, and hyperchromasia. Three LP cases (60%) showed a wild-type p53 pattern and 2 (40%) were confluent positive. Two dVIN cases (40%) showed full-thickness loss of differentiation. One case (20%) of dVIN was p53 negative, 2 (40%) were wild-type, 1 was confluent positive, and 1 showed dark suprabasilar staining. All cases were negative for p16. Compared with control, erosive LP epithelium showed a similar copy-number pattern, whereas the dVIN epithelium had many copy-number changes. CONCLUSIONS: A small subset of clinically diagnosed vulvovaginal erosive LP will show on histopathology a regenerative erosive vulvitis with loss of epithelial maturation and nuclear changes, which requires clinicopathologic correlation to distinguish from dVIN.