Seborrheic Keratoses - The Most Common Benign Skin Tumor of Humans. Clinical presentation and an update on pathogenesis and treatment options

Comparing the efficacy of plasma exeresis and cryotherapy for the treatment of seborrheic keratosis: A randomized controlled trial

BACKGROUND

Seborrheic keratoses (SK) is a benign epithelial skin tumor and plasma exeresis is a new technique.

AIMS

To compare the efficacy and safety of plasma exeresis and cryotherapy for treating SK.

METHODS

This study is a randomized controlled trial (RCT). One side of each patient was randomly treated with plasma exeresis (peak-to-peak voltage of 3.44 kV and a frequency of 62.5 kHz) and the other side with cryotherapy.

RESULTS

Thirty-five males were enrolled. At week 3, 37.1 % (N = 13) of lesions treated by plasma exeresis were clear, which was higher than those treated by cryotherapy 17.1% (N = 6). However, this difference was not significant (p-value: 0.06). At week 6, 16 (57.1 %) out of 28 remaining lesions, treated by plasma exeresis were clear, which was significantly higher (p-value: 0.005) than those completely cleared by cryotherapy in 6 out of 29 remaining lesions (20.7%). The mean physician assessment scale score was significantly reduced in both groups in the second follow-up (plasma group first follow-up 0.91 ± 0.89 vs. second follow-up 0.5 ± 0.64 and p-value: 0.0031; cryo group first follow-up 1.4 ± 0.84 vs. second follow-up 1.1 ± 0.72 and p-value: 0.0002). Regarding side effects, no significant difference was seen (p = 0.438). The most common complications in the plasma and cryotherapy groups were erythema (10/19, 52.63%) and hypo pigmentation (5/13, 38.46%).

CONCLUSIONS

Both cryotherapy and plasma exeresis are effective. We observed a significantly higher cleared lesions treated with plasma exeresis in 6 weeks and after two sessions.

An epidemiological study on skin tumors of the elderly in a community in Shanghai, China

The morbidity of skin tumors (ST) in China is a great concern as the population ages. No epidemiological survey on ST in elderly communities in China has been reported. A questionnaire survey was conducted among the residents over 60 years old in a community in Shanghai, China from May 1, 2011 to November 30, 2011. The prevalence of cutaneous tumors and associated factors were analyzed. Among 2038 valid cases, a total of 78 (3.8%, 95% CI 3.0-4.7) skin cancers (SC) were confirmed. According to the final multivariate regression analysis, age, gender and previous occupation were the significantly influential factors for SC. Actinic keratosis (AK) accounted for the largest proportion (63, 3.1%) in SC. The head and neck was the physiological site with the highest incidence of SC (64, 82.1%), and AK was the most common (55, 87.3%) in head and neck SC. The common concomitant diseases of SC were hypertension (26, 33.3%) and diabetes mellitus (9, 11.5%). Seborrheic keratosis (SK) was the most common benign skin tumor with a prevalence of 100%. Men and women developed SK in significantly different parts of the body (P < 0.0001). The incidence of ST in the elderly population in Shanghai community increased with age. ST preferred to occur in the head and neck, which might be attributed to excessive ultraviolet (UV) exposure in these areas. Therefore, early diagnosis and sun-protection education are essential interventions for ST in the elderly.

Perioral Clonal Variant of Seborrheic Keratosis: Diagnostic Challenges

Seborrheic keratosis is the most common benign tumour of epithelial origin, whose incidence increases with the advance of age. The aetiology of SK is not completely known but exposure to UV radiation may be an associated factor. Most of the cases have a rough, verrucous appearance, slightly elevated, and black or brown in colour. They are usually painless but at times present with pus discharge or ulceration.

Seborrheic keratosis

Seborrheic keratosis (SK) is the most common benign epidermal tumor in clinical dermatological practice. This review summarizes current knowledge about the clinical and histological appearance, epidemiology, pathogenesis, and treatment of SK. There are different subtypes of SK based on clinical presentation and histologic findings. Several factors, including age, genetic predisposition, and possibly also exposure to ultraviolet radiation, are thought to contribute to the development of SK. The lesions can occur on all areas of the body except for the palms and soles, but the most common sites are the face and upper trunk. The diagnosis is usually made clinically, and in some cases by dermatoscopy or histology. Many patients prefer to have the lesions removed for cosmetic reasons although there is no medical indication. Treatment options include surgical therapy, laser therapy, electrocautery, cryotherapy, and topical drug therapy, which is currently in development. Treatment should be individualized depending on the clinical picture and patient preference.

Update of pathophysiology and treatment options of seborrheic keratosis

Seborrheic keratosis (SK) is a common, benign tumor that can occur on everybody site and can be conservatively managed. Cosmetic concerns, especially when a lesion involves the facial area, are the most common reason for excision. SK shows male gender preponderance and increasing age is an independent association with the condition. Even though more prevalent in the elderly, it has also been reported in younger age groups like adolescents and young adults. Precise pathogenesis is still obscure, but ultra-violet exposure represents a predisposing factor to SK by altering the biochemical concentration and expression of factors like Glutamine deaminases, endothelin, and stem cell factor. Moreover, the accumulation of amyloid-associated protein has also been postulated. Involvement of genitalia has been associated with human papillomavirus infection. Recently, Merkel cell polyomavirus nucleic acid was also detected in SK. Several oncogenic mutations involving FGFR-3 and FOXN1 have been identified. SKs are usually classified clinically and histologically. Dermatoscopy is a noninvasive alternative diagnostic technique widely used in differentiating SK from other benign and malignant tumors. In terms of treatment, topical agents, shave dissection, cryosurgery, electrodesiccation, laser application and curettage under local anesthesia are safe methods for eradication of SKs, mostly for cosmetic purposes. Though generally safe, the latter techniques may occasionally cause post-procedure depigmentation, scarring, and recurrence. Nanosecond-pulsed electric field technology is a promising new technique with fewer side-effects.

Self-Assessment Questionnaire on Patient-Physician Concordance on Nevus Self-Count and Models Development to Predict High-Risk Phenotype >50 Nevi

BACKGROUND

Cutaneous melanoma accounts for the majority of skin cancer-related deaths. Readily identifiable phenotypic characteristics and total body nevus count (TBNC) >50 are among the most important risk factors for cutaneous melanoma. Implementation of nevus self-count procedures and self-assessment of phenotypic traits as part of skin self-examination could be an excellent screening tool for identifying an at-risk target population.

OBJECTIVES

Objectives of the study were to assess the skills of a central Italian and eastern Spanish population sample to recognize their skin lesions via the submission of a self-assessment questionnaire and to explore which self-assessment questionnaire item combination best predicts the high-risk condition of TBNC >50.

METHODS

Patients aged ≥18 years filled a self-assessment questionnaire, autonomously and prior to the dermatological visit. Subsequently, dermatologists performed total body skin examination and reported patients' skin lesions on a separate questionnaire.

RESULTS

We reported fair to moderate patient-dermatologist agreement for skin lesion self-assessment. The item number of nevi on the back was the single questionnaire item most accurately predicting TBNC >50. The high-sensitivity and high-specificity classification and regression tree models for the prediction of TBNC >50 displayed different items combinations; the item nevus on the back was always the first and most important predictor in both our models.

CONCLUSIONS

Patients were partially able to provide correct estimation of their whole-body nevus self-count. The item nevi on the back seems to be the first and most important predictor of TBNC >50 across our models. Delivery of high-sensitivity and high-specificity prediction models based on our questionnaire item combination may help defining a high-risk target population.

Effectiveness of a cosmetic device containing a combination of alpha- and beta-hydroxy acids, urea, and thuja for the treatment of seborrheic keratoses

BACKGROUND

Seborrheic keratosis is a benign epidermal tumor of cosmetic concern-as it progressively increases in size, thickness, and pigmentation-on which topical treatments are poorly effective. Considering its keratotic component, effective products may include active principles with keratolytic action.

AIMS

Evaluate the efficacy and tolerability of a topical cosmetic product with urea and hydroxy acids, in the treatment of seborrheic keratoses.

PATIENTS AND METHODS

Twenty patients were enrolled in an observational, prospective, open-label study. The topical device was applied on seborrheic keratoses twice daily for 30 days. We evaluated the progression of the treatment by clinical examination-using Daily Life Quality Index-and epiluminescence microscopy at baseline and day 30.

RESULTS

After 30 days of treatment, we documented a significant reduction in seborrheic keratosis thickness and number, which was confirmed also by epiluminescence microscopy. On day 30, global Daily Life Quality Index improved by 99.95%. The tolerability of the cosmetic device was considered excellent, according to 19/20 subjects (95%).

CONCLUSIONS

The results of our study showed the efficacy and tolerability of this cosmetic device. Its active compounds favor gradual removal of seborrheic keratoses, even in case of pigmented variants. This non-invasive treatment represents an alternative to surgical procedures, mainly for fragile patients and delicate skin areas. It is possible to speculate its usefulness in the topical treatment of circumscribed hyperkeratosis, palmoplantar keratoderma, and thick psoriatic plaques.

In vivo two-photon-excited cellular fluorescence of melanin, NAD(P)H, and keratin enables an accurate differential diagnosis of seborrheic keratosis and pigmented cutaneous melanoma

SIGNIFICANCE

Seborrheic keratoses (SKs) are harmless pigmented skin lesions (PSLs) that may be confused clinically not only with other benign conditions but also with cutaneous melanoma (CM). As SKs are one of the most common neoplasms in adults, the importance of their correct diagnosis is high. Misclassifying SK as malignant is not rare and leads to a high number of unnecessary biopsies. On the other hand, misdiagnosing CM as SK may have a large impact on prognosis or therapy.

AIM

In the non-invasive technique of dermatofluoroscopy, the fluorophores in melanocytes and keratinocytes are excited in vivo with nanosecond laser pulses and the resulting spectrally resolved, melanin-dominated fluorescence signals are used to differentiate between pigmented benign lesions and CM.

APPROACH

In this single-center, non-interventional study, 33 PSLs of 20 patients were scanned with dermatofluoroscopy in vivo. For all included cases, dermatofluoroscopic signals were compared to pathology classification.

RESULTS

The characteristic spectral features of SK were identified, where the signals are dominated by keratin, NAD(P)H, and melanin. The fluorescence spectra of SKs differed substantially from those of CM: a characteristic spectrum of SK has been identified in 27 of 28 SKs.

CONCLUSIONS

The high-accuracy differential diagnosis between CM and SK is possible with dermatofluoroscopy.

Inflammatory seborrheic keratosis resolution after hyperbaric oxygen therapy: Case presentation and pathophysiology review

Seborrheic keratosis (SK) is a common epidermal tumor, consisting of a benign proliferation of immature keratinocytes. The natural history of SK is a slow progression over time and complete remission is not expected. The article presents the first case of a complete resolution of a large (2.5 cm diameter) SK lesion after hyperbaric oxygen therapy (HBOT). In addition to the case presentation, the pathophysiology of SK and the potential beneficial physiological effects of HBOT are reviewed and discussed.

Usefulness of high-frequency ultrasound in differentiating basal cell carcinoma from common benign pigmented skin tumors

BACKGROUND

Basal cell carcinoma (BCC) is the most common cutaneous malignancy. Occasionally, it may have an appearance similar to that of some benign pigmented skin lesions. Therefore, additional information is needed to differentiate these lesions.

MATERIALS AND METHODS

A diagnostic accuracy study was performed from February 2018 to April 2019. All lesions underwent ultrasound examination with 50 and 20 MHz probes. The high-frequency ultrasound (HFUS) images were evaluated independently by 2 experienced doctors for the presence of predefined features, including the depth, shape, margin, anechoic area, hyperechoic spots, epidermal interrupted echo, mushroom sign, flat-bottom sign, and superficial hyperechoic focus (SHEF).

RESULTS

A total of 54 BCCs, 51 melanocytic nevi and 55 seborrheic keratoses (SK), were included. BCCs often involved the subcutaneous tissue (11/54, 20.4%; P < .001) and had an irregular shape (26/54, 48.1%; P < .001) and ill-defined borders (26/54, 48.1%; P < .001), while most benign pigmented lesions had a regular shape (101/106, 95.3%; P < .001) and well-defined borders (95/106, 89.6%; P < .001). BCCs occasionally showed anechoic areas (10/54, 18.5%; P < .001) and epidermal interrupted echo (18/54, 33.3%; P < .001). Moreover, hyperechoic spots could be found in BCCs (43/54, 79.6%), nevi (27/51, 52.9%), and SK (30, 54.5%) (P = .001), with mean number of 7.3, 5.5, and 8.0, respectively. The mushroom signs were all present in melanocytic nevi (18/51, 35.3%), while the flat-bottom sign (43/55, 78.2%; P < .001) and SHEF (40/55, 72.7%; P < .001) presented mainly in SKs.

CONCLUSIONS

Based on the typical features, HFUS could improve the accuracy of BCC identification and should be considered when dermatologists are unsure about the lesion type.

Hydrogen Peroxide 40% for the Treatment of Seborrheic Keratoses

OBJECTIVE

Hydrogen peroxide 40% (HP40) was approved by the US Food and Drug Administration for topical treatment of seborrheic keratosis (SK) in December 2017. This article will review phase II and III clinical trials to assess the drug's efficacy, safety, and clinical application.

DATA SOURCES

A systematic literature review was performed using the terms "Eskata AND seborrheic keratosis," and "hydrogen peroxide AND seborrheic keratosis" in the OVID MEDLINE, PubMed, Cochrane Library, EMBASE, and Web of Science databases. ClinicalTrials.gov was searched to identify ongoing or nonpublished studies.

STUDY SELECTION AND DATA ABSTRACTION

Articles written in English between January 2000 and mid-June 2020 discussing phase II and phase III clinical trials were evaluated.

DATA SYNTHESIS

In 2 phase III clinical trials, 4% and 8% of patients treated with HP40 had a Physician Lesion Assessment score of zero for all 4 SKs, respectively, compared with 0% in both vehicle groups at the primary end point of day 106 (P < 0.01; P < 0.0001).

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

HP40, although less effective, has a better safety profile than other treatment options. It should be especially considered for treatment of facial SKs, where it is most efficacious and where other treatment modalities, such as cryotherapy, are more challenging.

CONCLUSIONS

HP40 is a new, safe alternative treatment for SKs, although it is expensive and only modestly effective, both of which somewhat limit its overall utility. HP40 is a promising topical alternative, particularly for cosmetically sensitive locations, such as the face.

Dermatofluoroscopy diagnostics in different pigmented skin lesions: Strengths and weaknesses

BACKGROUND

The melanin fluorescence of skin lesions is measurable with two-photon excitation, a process termed dermatofluoroscopy, which has shown a shift from the green spectra in benign melanocytic lesions to the red spectra in melanoma. This study addressed the question as to which kind of pigmented lesions can be correctly diagnosed as melanin-bearing malignant tumors.

METHODS

476 pigmented lesions including 101 cutaneous melanomas were analyzed with dermatofluoroscopy, measuring the melanin fluorescence in a grid-like fashion with a separation of measurement points of 0.2 mm. The results of the dermatofluoroscopy are presented as a diagnostic score with a cut-off score of ≥ 28 for the diagnosis of melanin-bearing malignant tumors, and were compared to the gold standard of histopathology.

RESULTS

A highly significant difference (p < 0.0001) between the diagnostic scores of different skin tumors was found. Dermatofluoroscopy scores showed the highest sensitivity for melanomas (92.1 %). Interestingly, most pigmented basal cell carcinomas (BCCs, 88.9 %) were diagnosed as melanin-bearing malignant tumors. A higher sensitivity for the correct diagnosis was observed in older patients (≥ 53 years, p = 0.003), in patients with skin tanning (p = 0.025), and in patients with freckles during childhood (p = 0.046).

CONCLUSIONS

Two-photon fluorescence is an innovative technique for the diagnosis of pigmented skin lesions, and shows a high sensitivity for detection of melanomas and pigmented BCCs.

Guanine Deaminase Stimulates Ultraviolet-induced Keratinocyte Senescence in Seborrhoeic Keratosis via Guanine Metabolites

DNA damage and oxidative stress play a critical role in photoageing. Seborrhoeic keratosis (SK) affects sunlight-exposed sites in aged individuals. This study examined the mechanism of photoageing in SK. The guanine deaminase gene, which is involved in purine metabolism, was upregulated with uric acid levels and p21 in SK. Guanine deaminase was detectable in keratinocytes. Repeated exposure to ultraviolet (UV) increased levels of guanine deaminase, together with DNA damage, such as γ-H2AX and cyclobutane pyrimidine dimer formation, generation of reactive oxygen species, and keratinocyte senescence, which were reversed by guanine deaminase knockdown. However, guanine deaminase overexpression and H2O2 formed γ-H2AX, but not cyclobutane pyrimidine dimer. Loss-of-function guanine deaminase mutants reduced the metabolic end-product uric acid, which was increased by exposure to exogenous xanthine. Repeated exposure to UV increased levels of uric acid. Exogenous uric acid increased cellular senescence, reactive oxygen species, and γ-H2AX, similar to guanine deaminase. Overall, guanine deaminase upregulation increased UV-induced keratinocyte senescence in SK, via uric acid mediated by reactive oxygen species followed by DNA damage.

The color of skin: brown diseases of the skin, nails, and mucosa

Brown diseases comprise disorders leading to hyperpigmentation in skin and nails. Melasma is an acquired skin disorder that is characterized by brownish macules that typically occur on the face. Schamberg disease, also known as progressive pigmented purpura, is characterized by brown pigmentation with pepper spots on their edges. We summarize the epidemiology, pathogenesis, histologic features, and treatment choices for additional brown diseases, including melasma, pigmented purpuric dermatoses, postinflammatory hyperpigmentation, drug-induced hyperpigmentation, and pigmentations due to systemic or physiologic conditions.

Recent advances in managing and understanding seborrheic keratosis

Seborrheic keratosis (SK) is a common benign epidermal tumor with predominance in adult patients. Whereas common SKs are more frequent in Caucasians, dermatosis papulosa nigra is more prevalent in patients with a Fitzpatrick skin type of at least 3. There seems to be a link between extrinsic skin aging and the occurrence of SK. Mutations of fibroblast growth factor receptor 3 and other signaling molecules are a frequent finding in SK lesions. However, this does not translate into any malignant potential. Viral infections are particularly common in genital lesions, although their pathogenetic relevance for SK is questionable. Different histologic and clinical subtypes have been identified. The great variability of SKs raises some difficulties in diagnosis. Dermoscopy is the preferred non-invasive diagnostic method, in particular to differentiate pigmented SKs from other pigment tumors, including cutaneous melanoma. Eruptive SKs can be a paraneoplastic condition known as the Leser–Trélat sign. New targeted cancer treatments can cause a pseudo-Leser–Trélat sign. The treatment in practice is mainly minor surgery, including cryosurgery, shave excisions, and laser-assisted removal. The medical approaches have only limited effects. Recently, two formulations for topical therapy have been evaluated: a product with 40% hydrogen peroxide (HP40) and an aqueous nitric–zinc complex. Based on clinical trials, HP40 seems to be a promising alternative to surgery, in particular for facial lesions.