Ki67 expression in lichen sclerosus of vulva in patients with and without associated squamous cell carcinoma

Topical Corticosteroids in the Treatment of Vulvar Lichen Sclerosus: A Review of Pharmacokinetics and Recommended Dosing Frequencies

Topical corticosteroids are often utilized as the first-line treatment for vulvar lichen sclerosus (VLS). However, there is wide variability in dosing regimens, as well as a lack of consensus on maintenance dosing. Available guidelines on dosing frequency and regimen continuation for VLS are based on clinical expert opinion and do not necessarily reflect the pharmacokinetics of topical corticosteroids. Over the past few decades, there have been many advances in the techniques used to measure the local and systemic absorption of topical corticosteroids. These techniques have led to a greater understanding of the pharmacokinetics and bioavailabilities of these medications. However, it is not clear how this new information has been applied in evaluating dosing regimens and commonly cited risks when considering short- and long-term use in different vulvar dermatoses. This purpose of this review is to evaluate the available evidence on pharmacokinetics, absorption rates, and concentration levels of topical corticosteroids in lesional and nonlesional skin. Additionally, the evidence regarding commonly cited risks of topical corticosteroid use, including dermal thinning, adrenal suppression, systemic immunosuppression, and tachyphylaxis are reviewed. Differences in the effects of topical corticosteroids on the varied tissues of the vulva are specifically explored. Finally, these considerations are applied to evaluate the current treatment guidelines for VLS to provide direction in determining an evidenced-based dosing regimen and to inform future research in this area. Mautz TT, Krapf JM, Goldstein AT. Topical Corticosteroids in the Treatment of Vulvar Lichen Sclerosus: A Review of Pharmacokinetics and Recommended Dosing Frequencies. Sex Med Rev 2021;XX:XXX-XXX.

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.

Differentiated Vulvar Intraepithelial Neoplasia: A Brief Review of Clinicopathologic Features

Differentiated-type vulvar intraepithelial neoplasia (dVIN) is a non–human papilloma virus (HPV)-related precursor lesion to vulvar squamous carcinoma. The terminology has only become recognized clinically and histopathologically in recent years despite being described more than 50 years ago. As opposed to the HPV-related VIN (uVIN), dVIN has different features of histomorphology, risk of progression, and molecular pathogenesis. Notably, dVIN commonly develops in a background of chronic inflammatory dermatoses such as lichen sclerosis and lichen simplex chronicus. The recognition of dVIN remains a challenge owing to lack of accurate and reproducible diagnostic criteria. Morphologically, basal layer atypia, dyskeratosis, and elongation and anastomosis of the rete ridges are regarded as very useful diagnostic features. Ancillary tests can be very helpful to establish a definitive diagnosis in some ambiguous cases. In contrast to uVIN, dVIN is more likely to progress to vulvar squamous carcinoma in a shorter period. The goal of this review is to elaborate on the clinicopathologic characteristics and underline the key histologic features that best facilitate the diagnosis of dVIN.

Immunohistochemistry in Gynecologic Pathology: An Example-Based Practical Update

CONTEXT

- Immunohistochemical stains are routinely applied in the pathology diagnostic workup of gynecologic lesions. The rapidly expanding repertoire of available markers helps in refining the diagnostic criteria for each disease entity; however, limitations and pitfalls exist.

OBJECTIVE

- To provide a practical, relevant update on the use of immunohistochemistry for commonly encountered differential diagnoses in gynecologic pathology.

DATA SOURCES

- Literature review and authors' diagnostic experience.

CONCLUSIONS

- Immunohistochemistry is a helpful adjunct tool in gynecologic pathology. Although the primary application is in the diagnostic workup, novel prognostic and predictive markers, and immunostains to screen for genetic cancer syndromes, have also been recently introduced in the field.

Squamous precursor lesions of the vulva: current classification and diagnostic challenges

Growing evidence has established two major types of vulvar intraepithelial neoplasia (VIN), which correspond to two distinct oncogenic pathways to vulvar squamous cell carcinoma (VSCC). While the incidence of VSCC has remained relatively stable over the last three decades, the incidence of VIN has increased. VIN of usual type (uVIN) is human papillomavirus (HPV)-driven, affects younger women and is a multicentric disease. In contrast, VIN of differentiated type (dVIN) occurs in post-menopausal women and develops independent of HPV infection. dVIN often arises in a background of lichen sclerosus and chronic inflammatory dermatoses. Although isolated dVIN is significantly less common than uVIN, dVIN bears a greater risk for malignant transformation to VSCC and progresses over a shorter time interval. On histological examination, uVIN displays conspicuous architectural and cytological abnormalities, while the morphological features that characterise dVIN are much more subtle and raise a wide differential diagnosis. On the molecular level, dVIN is characterised by a higher number of somatic mutations, particularly in TP53. Here we review the classification, epidemiology, clinical features, histomorphology, ancillary markers and molecular genetics of both types of VIN, and discuss the morphological challenges faced by pathologists in interpreting these lesions.

Evaluation of cervical mucosa in transmission bottleneck during acute HIV-1 infection using a cervical tissue-based organ culture

Background

Although there are different strains of HIV-1 in a chronically infected individual, only one or limited virus strains are successfully transmitted to a new individual. The reason for this “transmission bottleneck” is as yet unknown.

Methodology/Principal Findings

A human cervical explant model was used to measure HIV-1 transmission efficiency of viral strains from chronic infections, and transmitter/founder variants. We also evaluated the genetic characteristics of HIV-1 variants in the inoculums compared to those transmitted across the cervical mucosa. Eight different HIV-1 isolates were used in this study, six chronic isolates and two transmitter/founder viruses. The transmission efficiency of the chronic and transmitter/founder virus isolates and the viral diversity of chronic isolates before and after viral transmission were assessed. The results indicate that transmitter/founder viruses did not display higher transmission efficiency than chronic HIV-1 isolates. Furthermore, no evidence for a difference in diversity was found between the inoculums and transmitted virus strains. Phylogenetic analysis indicated that the sequences of variants in the inoculums and those present in transmitted virus intermingled irrespective of co-receptor usage. In addition, the inoculum and transmitted variants had a similar pairwise distance distribution.

Conclusion

There was no selection of a single or limited number of viral variants during HIV-1 transmission across the cervical mucosa in the organ culture model, indicating that the cervical mucosa alone may not produce the transmission bottleneck of HIV-1 infection observed in vivo.

Ingrown toenail: histopathologic and immunohistochemical study

Although ingrown toenail (IT) is a common problem, the morphologic alterations presented in this condition have rarely been presented in literature. We have studied 14 cases from 12 different patients and studied the biopsies of all of them, not only with routine techniques but also with histochemical stains (Masson trichrome, periodic acid-Schiff, and Gram) and with immunohistochemical techniques mindbomb homolog-1 (MIB-1), p63, D2-40, and AE1-AE3). The patients were clinically classified into 4 stages (1, 2a, 2b, and 3). The main changes evidenced were ingrowing of the squamous epithelium (either from the matrix or mostly from the hyponichium) and chronic plasma-cell rich inflammation with prominent vascularization. The intensity of these changes varied depending on the stage: whereas they were mild in stages 1 and 2a, they were prominent in stages 2b and 3. In advanced stages, the epithelial nests showed certain dyskeratosis. The expression of MIB-1 was, nevertheless, only basal and parabasal. p63 was intensively expressed by the epithelial nests. We therefore conclude that (a) IT shows epithelial ingrowing with accompanying granulation tissue; (b) according to the clinical stage of the disease, this pattern can be more or less complex; (c) in advanced stages of IT, the pattern can mimic a well-differentiated squamous cell carcinoma; (d) MIB-1 is not helpful in distinguishing IT from squamous cell carcinoma; (e) the high expression of p63 by the ingrowing epithelium should not be the source of a misdiagnosis of malignancy.

A comparative analysis of lichen sclerosus of the vulva and lichen sclerosus that evolves to vulvar squamous cell carcinoma

OBJECTIVE

The aim of this study was to determine whether the premalignant change in lichen sclerosus (LS) could be identified with immunohistochemical analyses.

STUDY DESIGN

Eight cases of histologically diagnosed vulvar LS, which showed, after a period of 10 months-9 years, an evolution to carcinoma of the vulva that was histologically documented, were compared with 8 cases of vulvar LS, for which follow-up information was available for at least 9 years. The proliferative index and the expression of tumor suppressors p16 and p53 were analyzed.

RESULTS

The difference of MIB1 labeling index of evolving or unchanged LS cases was significant (P = .005). The difference in the p53 of evolving or unchanged LS cases shows a trend towards association (P = .08). Both LS cases (evolving or unchanged) did not show p16 positive staining.

CONCLUSION

The evaluation of MIB1 and p53 may identify those vulvar LS cases with a high likelihood of evolving into squamous cell carcinoma, which would need careful periodic checks or adjunctive biopsies. The study must be confirmed by a larger number of cases to substantiate this observation.

MIB1 expression in basal cell layer: a diagnostic tool to identify premalignancies of the vulva

Lichen sclerosus, high-grade usual vulvar intraepithelial neoplasia (VIN) and differentiated VIN have a different malignant potential. The objective of this study was to quantify the proliferative activity in the basal region of the epithelium of vulvar premalignancies. Furthermore, we investigated whether MIB1 expression in the basal region of vulvar epithelium can be helpful in diagnosing differentiated VIN, which may be hard to discern from normal epithelium. MIB1 was used to immunohistochemically visualise proliferating cells within formalin-fixed, paraffin-embedded, archival tissue sections of different vulvar premalignancies (N=48) and normal vulvar epithelium (N=16). Automatic digital image analysis software was developed to quantify the proliferating fraction in different parts of the epithelium (MIB1 positivity index). MIB1 expression differed among the various vulvar premalignancies; a MIB1-negative basal cell layer was a distinct feature of normal vulvar epithelium. No MIB1-negative basal cell layer was noted in differentiated VIN or other vulvar premalignancies. Owing to this negative cell layer, the MIB1 proliferation index in normal vulvar epithelium was significantly lower than in vulvar premalignancies. In conclusion, MIB1 expression can be a helpful tool in diagnosing a premalignancy and has additional value especially to distinguish differentiated VIN neoplasia from normal vulvar epithelium, but cannot explain the differences in malignant potential.

Low-grade vulvar and vaginal intraepithelial neoplasia: correlation of histologic features with human papillomavirus DNA detection and MIB-1 immunostaining

Histologic criteria of low-grade vulvar/vaginal intraepithelial neoplasia (VIN1/VAIN1) are well established; however, a significant interobserver variability in diagnosing VIN1/VAIN1 has been reported. The goal of this study was to evaluate the utility of MIB-1 immunostaining as an adjunct test to increase the diagnostic accuracy in equivocal cases of VIN1/VAIN1. The second goal was to examine the distribution of low- and high-oncogenic risk human papillomaviruses (HPVs) in VIN1/VAIN1 lesions. Consecutive vulvar/vaginal biopsies originally diagnosed as VIN1/VAIN1 (n = 43) or benign (n = 20) were reviewed by two pathologists to obtain a consensus diagnosis. The diagnosis was further confirmed with HPV testing using Short PCR Fragment 10 and Line Probe Assay. MIB-1 immunostaining was performed, and positive staining was defined as a cluster of two or more stained nuclei in the upper two thirds of the epithelial thickness. After verification of the diagnosis using the consensus histologic review and HPV detection as an objective confirmatory test, 31% of cases originally diagnosed as VIN1/VAIN1 were identified as being overdiagnosed. The sensitivity and the specificity of MIB-1 staining for identifying VIN1/VAIN1 were 0.96 and 0.90, respectively. Seventy percent of VIN1 cases were associated with low-risk viral types. In contrast, the majority (84%) of VAIN1 cases were associated with high-risk HPVs. In conclusion, MIB-1 staining is sensitive and specific for identifying VIN1/VAIN1, helpful in verifying the diagnosis in equivocal cases.

Histology of lichen sclerosus varies according to site and proximity to carcinoma

To investigate why vulvar but not extragenital lichen sclerosus is associated with squamous cell carcinoma, we performed a histologic study of extragenital lichen sclerosus, vulvar lichen sclerosus without carcinoma, and vulvar lichen sclerosus with carcinoma adjacent to and distant from the carcinoma. We compared epidermal thickness, rete ridge length, mitotic activity, atypia, dermal collagen change, dermal inflammation, and presence of other dermatoses in 30 women in each group. Extragenital lichen sclerosus showed thinner epidermis (mean thickness of 0.13 mm versus 0.41 mm; P < 0.0005), shorter rete ridges (P = 0.0001), more dermal edema (P = 0.16), and absence of associated dermatoses of spongiotic dermatitis and lichen planus (P < 0.005) compared with vulvar lichen sclerosus. The epidermal thickening seen in vulvar lichen sclerosus was indistinguishable from lichen simplex chronicus. Vulvar lichen sclerosus without carcinoma was generally similar to that distant from carcinoma. Vulvar lichen sclerosus adjacent to carcinoma showed increased epidermal thickness (0.61 mm versus 0.26 mm; P < 0.005), more dermal fibrosis (P < 0.0005), more inflammation (P < 0.0005), and more simplex (differentiated) vulvar intraepithelial neoplasia (18 cases versus 1 case; P < 0.0005) compared with that distant from carcinoma. We concluded that (1) the classic histologic features of lichen sclerosus are seen in both vulvar and extragenital sites; (2) vulvar lichen sclerosus without associated carcinoma has a mean epidermal thickness more than three times that of extragenital lichen sclerosus; (3) the epidermal thickening is histologically indistinguishable from lichen simplex chronicus; (4) there is a tendency for vulvar lichen sclerosus to have a more sclerotic and inflamed dermis; (5) lichen sclerosus 10 mm from cancer is more similar to vulvar lichen sclerosus without carcinoma than lichen sclerosus 1 mm from carcinoma; and (6) lichen sclerosus adjacent to carcinoma tends to show exaggerated epidermis thickness, basal atypia, and loss of the edematous-hyaline layer.

Concordant p53 and mdm-2 protein expression in vulvar squamous cell carcinoma and adjacent lichen sclerosus

To determine if carcinogenic events in vulvar skin precede the onset of morphologic atypia, the authors investigated for derangements in DNA content, cell proliferation, and cell death in vulvar carcinomas and surrounding skin in 140 samples of tumor and surrounding skin collected from 35 consecutive vulvectomy specimen for squamous cell carcinoma (SCC) or vulvar intraepithelial neoplasia (VIN) 3. Vulvar non-cancer excisions were used as controls. Investigations consisted of histologic classification and measurement of 9 variables--epidermal thickness (acanthosis and rete ridge length), immunolabeling index (LI) for 3 proteins (p53 protein, Ki-67, and mdm-2), pattern of p53 expression (dispersed vs. compact), DNA content index, and presence of aneuploidy by image analysis and apoptotic rate by Apotag labeling. Significant positive correlations were found for all nine variables studied versus increasing histologic severity in two proposed histologic stepwise models of vulvar carcinogenesis (lichen sclerosus (LS) and VIN 3 undifferentiated associated SCC groups). High p53 LI (>25) and the compact pattern of p53 expression (suspected oncoprotein) significantly correlated with LS and its associated vulvar samples compared with samples not associated with LS (P < or = 0.001). Furthermore, p53 LI, mdm-2 LI, and pattern of p53 expression were concordant between patient matched samples of LS and SCC. In addition, mdm-2 LI significantly correlated with dispersed pattern p53 LI suggesting a response to wild-type p53 protein accumulation. These findings support the hypothesis that neoplastic transformation occurs in sequential steps and compromises proteins involved in the cell cycle control. Concordance of p53 and mdm-2 protein expression in LS and adjacent SCC provides evidence that LS can act as a precursor lesion in the absence of morphologic atypia. Overexpression of mdm-2 with stabilization and inactivation of p53 protein may provide an alternate pathway for vulvar carcinogenesis.

MIB-1 immunostaining is a beneficial adjunct test for accurate diagnosis of vulvar condyloma acuminatum

The histopathologic diagnosis of vulvar condyloma acuminatum is often based on architectural features that are not specific for human papillomavirus (HPV) infection. Because HPV-associated lesions show increased cellular proliferation, the authors evaluated the usefulness of MIB-1 immunostaining as an aid in the differential diagnosis of cases equivocal for condyloma. The MIB-1 immunostaining pattern was correlated with HPV DNA detection in condyloma acuminatum (CON-A; n = 15), "consistent with condyloma" (c/w CON-A; n = 26), fibroepithelial polyp (FEP; n = 14), and squamous papilloma (n = 10). HPV was detected in 100% of the CON-A cases, and all cases demonstrated MIB-1-positive nuclei in the upper two thirds of the epithelial thickness. With this definition of MIB-1 positivity, there was complete concordance between MIB-1 positivity and HPV detection for all cases (kappa = 0.88). Of the cases c/w CON-A, 17 of 26 (65%) were positive for both MIB-1 and HPV, and could be reclassified as CON-A, whereas 35% were identified as an overdiagnosis based on negative results. In addition, two cases of FEP were MIB-1 and HPV positive, and thus were identified as an underdiagnosis. These results suggest significant overdiagnosis of cases equivocal for condyloma, and indicate that MIB-1 immunostaining is a beneficial adjunctive test when the morphologic features are suggestive but not diagnostic for CON-A.