A literature review

Lichen sclerosus: A C5B-9 mediated chronic microvascular injury syndrome potentially reflective of common adult comorbidities

Lichen sclerosus (LS) is a cutaneous disease of unknown etiology that often involves the vulva or foreskin but also can affect extragenital sites. Regardless of the anatomic site, the histomorphology and presumably pathogenesis are similar. Perhaps a clue to the pathophysiology of LS lies in its frequent association with morphea, specifically, when occurring in an extragenital context. In our experience a striking feature evident in established lichen sclerosis (LS) is one of superficial vascular drop out whereby residual vessels exhibited endothelial cell necrosis and microvascular basement membrane zone thickening, the latter reflective of antecedent episodes of microvascular injury. We sought to understand the pathophysiology that underlies the distinct vascular changes and in doing so, shed light on the pathogenesis of LS. We examined 44 cases of LS over a period of 2019 to 2021. We were able to obtain past medical histories in 34 of the 44 cases. Regarding pathological assessment, the predominant focus was on microvascular changes. We assessed the role of C5b-9 mediated vascular injury in the pathogenesis of the vasculopathy and enhanced type I interferon signaling in vessels given the morphologic semblance to the select interferonopathy syndromes, namely fibrosing dermatomyositis and Kohlmeier Degos disease. We examined the expression of CMV DNA and protein based on prior observations in an earlier study that isolated early protein expression in the microvasculature in the setting of LS and scleroderma. From a clinical perspective, the most striking association was an older age at the time of diagnosis (mean age of 62 years and median age of 61.5 years) and the presence of vascular comorbidities of diabetes, hypertension, and hyperlipidemia in almost 80% of cases. All cases showed significant microvascular changes in the superficial corium with the most frequent findings being those of significant basement membrane zone reduplication and vascular drop out. A number of cases showed prominent microvascular deposits of C5b-9 in the zone of hyalinizing fibrosis or subjacent to the discernible table of fibroplasia in the absence of enhanced type I interferon signaling. In no case were there viral cytopathic changes associated with CMV affecting the endothelium. The studies that encode CMV DNA or protein did not show a significant role for CMV reactivation in endothelium in the majority of the studied cases. It is concluded that the pathophysiology of LS includes a microvascular injury syndrome within the papillary dermis. The mechanism of endothelial cell injury is complement mediated at least in part and could reflect an adaptive immune response targeting endothelium indicative of classic complement pathway activation when coexisting with morphea or occurring in younger individuals. A non-immune based endothelial dysfunction and complement mediated injury unrelated to antibody driven classic complement pathway activation are more likely pathogenetically in the setting of certain diseases like diabetes mellitus and hypertension. Vascular drop out can be explained by the diminished endothelial progenitor pool needed to repopulate the damaged microvessels in certain settings like hypertension and diabetes.

A Scoping Review and Population Study Regarding Prevalence and Histopathology of Juvenile Vulvar Melanocytic Lesions. A Recommendation

Cases of vulvar melanocytic lesions in juveniles are rarely reported. We analyze the evidence regarding vulvar melanocytic lesions in juveniles with or without vulvar lichen sclerosus to help decision making by clinicians and pathologists. A scoping review on vulvar melanocytic lesions with or without vulvar lichen sclerosus, including malignant vulvar melanomas, in females up to age 18 years was performed. In addition, the histopathology records of the cohort of all such lesions in The Netherlands from 1991 through 2020 were investigated, and a structured analysis of tissue samples of the subset of cases with lichen sclerosus was performed. The literature study performed confirms that vulvar melanomas in juveniles are extremely rare and that published case reports are often disputed. In The Netherlands, there are no cases of malignant vulvar melanomas up to age 18 years recorded from 1991 through 2020. Atypical histopathological features are often found in biopsies of vulvar nevi in juveniles, especially with concomitant lichen sclerosus, confirming earlier case studies in the literature. We conclude that even with atypical findings, vulvar melanocytic lesions in juveniles have a benign course. To avoid unnecessary and possibly mutilating procedures, we advise referral to an expert center and adaption of existing guidelines for vulvar melanocytic lesions in juveniles.

Comparison of lichen sclerosus in boys and girls: A systematic literature review of epidemiology, symptoms, genetic background, risk factors, treatment, and prognosis

BACKGROUND

Studies concerning pediatric lichen sclerosus are limited, and, to date, there have been no studies comparing the course of lichen sclerosus in boys and girls. We sought to examine all publications on boys and girls with lichen sclerosus and assess and compare epidemiology, symptoms and signs, genetic background, risk factors, treatment, and prognosis.

METHODS

A systematic search was performed in the Embase, Medline, Cochrane, and Web of Science databases. Inclusion criteria were information on children ages 0-18 years and a clinical or histologic diagnosis of lichen sclerosus. Literature from 1985 to 2021 was reviewed.

RESULTS

A total of 1780 articles were retrieved from the search, of which 90 articles were eligible for inclusion. Boys and girls present similarly on many aspects; nonetheless, treatment and follow-up are approached differently.

CONCLUSIONS

Though the clinical approach is often different, lichen sclerosus in boys and girls demonstrates many similarities. More research is needed, especially on follow-up, to gain a better understanding of the course of lichen sclerosus and establish an advanced management plan for children.

Structured analysis of histopathological characteristics of vulvar lichen sclerosus in a juvenile population

Genital lichen sclerosus (LS), a chronic noninfectious dermatosis, is not rare in pediatric dermatology. The histopathological diagnosis in children and adults in both genital and nongenital LS is considered to be the same and encompasses a broad range of possible characteristics. Clinical manifestations and treatment options of genital LS in children are different depending on gender. The vast majority of boys are treated with circumcision, making for a larger amount of information on the histopathology of genital LS in boys, whereas substantial information on the histopathology of juvenile vulvar LS is lacking. In girls, vulvar LS almost always persists beyond puberty and, therefore, presents a particular challenge to clinicians and cause for concern for the patient. Vulvar LS in childhood and adolescence (juveniles) is underreported, and there are uncertainties with regard to the long-term course of the disease when it occurs at an age when the vulva is still developing. The present study investigates biopsies of 100 juvenile cases of vulvar LS and analyzes the presence or absence of the most salient histopathological characteristics of LS that are described in the literature. We found that the range of histopathological characteristics known for adult LS are also present in juvenile vulvar LS, even at very young ages, including histopathological features associated with autoimmune disease, in support of the idea of a similar pathogenesis.

Pediatric vulvar malignancies: rare but important to know

Malignancies of the vulva in the pediatric population are exceptionally rare, which makes it difficult to gain any insight into their clinicopathologic profile. In this review, we summarize all published cases of a vulva malignancy in pediatric patients (≤21 years) reported in the English language literature for the 50-year period between 1970 and 2020. We estimate that less than 100 malignancies have been reported in total, approximately 50% of which were rhabdomyosarcomas. Invasive squamous cell carcinomas, yolk sac tumors, Ewing sarcoma/primitive neuroectodermal tumors (ES/PNET) and melanomas each represented approximately 10% of reported cases. For rhabdomyosarcoma, the alveolar and embryonal subtypes were reported with equal frequency, with both representing 70% of cases combined. The average patient age was 9.8 years. 48% and 35% were Intergroup Rhabdomyosarcoma Study clinical groupings I and III respectively. Managements were generally multimodal, and overall outcomes for the group were favorable. For invasive squamous cell carcinoma, the patients were all in their teenage years, with an average age at diagnosis of 15.2 years. A small subset of cases were associated with human papillomavirus and immunosuppression, and it is possible that immunosuppression has a role in vulvar squamous carcinogenesis in this population. One case was associated with lichen sclerosus. The patients with yolk sac tumors ranged in age from less than 1 year to 20 years (mean 12) and 67% of cases were stage I at presentation. An insufficient number of cases have been reported to define their prognosis, although some cases were notably aggressive. The few reported cases of melanoma are distinctive only because they were all associated with lichen sclerosus, suggestive of some role for the latter in their pathogenesis. The average age of patients reported with ES/PNET was 15 years (range 3.3 to 20). At least half of the reported cases were advanced stage at presentation, and patient outcomes were notably poor: 62.5% were dead of disease at follow-up. Pediatric vulvar malignancies are rare and are mostly comprised of 5 entities. Their accurate pathologic classification is necessary to facilitate optimal management.

Common and not so Common Melanocytic Lesions in Children and Adolescents

The acquired melanocytic nevus is the most common lesion encountered by pediatric pathologists and dermatopathologists in their daily practice. In most cases, there are few difficulties in histopathologic diagnosis. However, it is the acquired melanocytic lesion known as the Spitz nevus, with its intrinsic atypical features which becomes the challenge since it exists along a histopathologic and biologic continuum from the atypical Spitz tumor to spitzoid melanoma. The frustration with some of these spitzoid lesions is that even the "experts" cannot agree as to the differentiation of one from the other even at the level of molecular genetics. Other melanocytic lesions are discussed including the congenital melanocytic nevus with its proliferative nodule(s) and melanoma as the ultimate complication. Although uncommon, cutaneous melanoma in the first 2 decades is emerging as a clinical problem especially in young women in the second decade of life. These are ultraviolet-associated neoplasms whose histopathologic and prognostic features are identical to the adult experience. Considerable progress has been made over the past 15 to 20 years in our understanding of cutaneous melanocytic lesions, but gaps still exist in the important group of spitzoid lesions. It can also be anticipated that more cutaneous melanomas in children will be seen in the future based upon epidemiologic studies.

Pathology and genomics of pediatric melanoma: A critical reexamination and new insights

The clinicopathologic features of pediatric melanoma are distinct from those of the adult counterpart. For example, most childhood melanomas exhibit a uniquely favorable biologic behavior, save for those arising in large/giant congenital nevi. Recent studies suggest that the characteristically favorable biologic behavior of childhood melanoma may be related to extreme telomere shortening and dysfunction in the cancer cells. Herein, we review the genomic profiles that have been defined for the different subtypes of pediatric melanoma and particularly emphasize the potential prognostic value of telomerase reverse transcriptase alterations for these tumors.

Vulvovaginitis- presentation of more common problems in pediatric and adolescent gynecology

Vulvovaginitis is one of the most common gynecological complaints presenting in the pediatric and adolescent female. The common causes of vulvovaginitis in the pediatric patient differ than that considered in adolescent females. When a child present with vulvar itching, burning and irritation the most common etiology is non-specific and hygiene measures are recommended. However these symptoms can mimic more serious etiologies including infection, labial adhesion, lichen sclerosis, pinworms and foreign body must be considered. Yeast infection is rare in the pediatric population but common in the adolescent. In the adolescent patient infections are more common. Yeast and bacterial vaginosis are commonly seen but due to the higher rate of sexual activity in this population sexually transmitted infections must also be considered.

Male genital lichen sclerosus

Male genital lichen sclerosus (MGLSc) is a chronic inflammatory skin disease responsible for male sexual dyspareunia and urological morbidity. An afeared complication is squamous cell carcinoma (SCC) of the penis. The precise etiopathogenesis of MGLSc remains controversial although genetic, autoimmune and infective (such as human papillomavirus (HPV) hepatitis C (HCV), Epstein-Barr virus (EBV) and Borrelia) factors have been implicated: Consideration of all the evidence suggests that chronic exposure of susceptible epithelium to urinary occlusion by the foreskin seems the most likely pathomechanism. The mainstay of treatment is topical ultrapotent corticosteroid therapy. Surgery is indicated for cases unresponsive to topical corticosteroid therapy, phimosis, meatal stenosis, urethral stricture, carcinoma in situ (CIS) and squamous cell carcinoma.

Update on melanocytic nevi in children

A new or changing melanocytic nevus in a child or adolescent often leads to concern in parents and physicians. To avoid undue alarm and unnecessary procedures, dermatologists should be aware of the natural history and clinical spectrum of nevi in pediatric patients, as well as findings that are potentially worrisome in this age group. This review provides an update on melanocytic nevi in children, focusing on their dynamic evolution over time, molecular insights into nevogenesis, and phenotypic markers for increased risk of melanoma in adolescence and adulthood. Special considerations for Spitz nevi and nevi located in particular sites (eg, scalp, acral, genital) are highlighted. Current understanding of the risks associated with congenital melanocytic nevi of different sizes and strategies for the management of children with numerous acquired nevi, Spitz nevi, and congenital nevi are also discussed.

Investigation of cAMP microdomains as a path to novel cancer diagnostics

Understanding of cAMP signaling has greatly improved over the past decade. The advent of live cell imaging techniques and more specific pharmacologic modulators has led to an improved understanding of the intricacies by which cAMP is able to modulate such a wide variety of cellular pathways. It is now appreciated that cAMP is able to activate multiple effector proteins at distinct areas in the cell leading to the activation of very different downstream targets. The investigation of signaling proteins in cancer is a common route to the development of diagnostic tools, prognostic tools, and/or therapeutic targets, and in this review we highlight how investigation of cAMP signaling microdomains driven by the soluble adenylyl cyclase in different cancers has led to the development of a novel cancer biomarker. Antibodies directed against the soluble adenylyl cyclase (sAC) are highly specific markers for melanoma especially for lentigo maligna melanoma and are being described as "second generation" cancer diagnostics, which are diagnostics that determine the 'state' of a cell and not just identify the cell type. Due to the wide presence of cAMP signaling pathways in cancer, we predict that further investigation of both sAC and other cAMP microdomains will lead to additional cancer biomarkers. This article is part of a Special Issue entitled: The role of soluble adenylyl cyclase in health and disease.