The clinical and dermoscopic features of invasive cutaneous squamous cell carcinoma depend on the histopathological grade of differentiation

Dermoscopy of Squamous Cell Carcinoma: From Actinic Keratosis to Invasive Forms

When performing the dermoscopy of squamous cell carcinoma and its precursors we differentiate among keratin-related, vascular, and pigment-related criteria. Non-pigmented actinic keratoses are characterized by the "strawberry pattern". Pigmented actinic keratosis shows a significant dermatoscopic overlap with lentigo maligna, but the presence of pigmented scales, erythema, and prominent follicles favors its diagnosis. Bowen's disease is characterized by clustered glomerular vessels, white-yellowish scales, and brown or grey dots arranged in lines in its pigmented variant. Finally, dermoscopy allows us to detect invasive squamous cell carcinoma in its early stages and differentiate it from its precursors. Furthermore, its presentation may vary depending on the degree of differentiation, with keratin-associated criteria predominating in well-differentiated tumors, while the atypical vascular pattern will predominate in poorly differentiated tumors.

[Translated article] Dermoscopy of Squamous Cell Carcinoma: From Actinic Keratosis to Invasive Forms

When the dermoscopy of squamous cell carcinoma and its precursors we differentiate among keratin-related, vascular, and pigment-related criteria. Non-pigmented actinic keratoses are characterized by the "strawberry pattern". Pigmented actinic keratosis shows a significant dermatoscopic overlap with lentigo maligna, but the presence of pigmented scales, erythema, and prominent follicles favors its diagnosis. Bowen's disease is characterized by clustered glomerular vessels, white-yellowish scales, and brown or grey dots arranged in lines in its pigmented variant. Finally, dermoscopy allows us to detect invasive squamous cell carcinoma in its early stages and differentiate it from its precursors. Furthermore, its presentation may vary depending on the degree of differentiation, with keratin-associated criteria predominating in well-differentiated tumors, while an atypical vascular pattern will predominate in poorly differentiated tumors.

Using computational learning for non-melanoma skin cancer and actinic keratosis near-infrared hyperspectral signature classification

BACKGROUND

The early detection of Non-Melanoma Skin Cancer (NMSC) is essential to ensure patients receive the most effective treatment. Diagnostic screening tools for NMSC are crucial due to high confusion rates with other types of skin lesions, such as Actinic Keratosis. Nevertheless, current means of diagnosing and screening patients rely on either visual criteria, that are often conditioned by subjectivity and experience, or highly invasive, slow, and costly methods, such as histological diagnoses. From this, the objectives of the present study are to test if classification accuracies improve in the Near-Infrared region of the electromagnetic spectrum, as opposed to previous research in shorter wavelengths.

METHODS

This study utilizes near-infrared hyperspectral imaging, within the range of 900.6 and 1454.8 nm. Images were captured for a total of 125 patients, including 66 patients with Basal Cell Carcinoma, 42 with cutaneous Squamous Cell Carcinoma, and 17 with Actinic Keratosis, to differentiate between healthy and unhealthy skin lesions. A combination of hybrid convolutional neural networks (for feature extraction) and support vector machine algorithms (as a final activation layer) was employed for analysis. In addition, we test whether transfer learning is feasible from networks trained on shorter wavelengths of the electromagnetic spectrum.

RESULTS

The implemented method achieved a general accuracy of over 80 %, with some tasks reaching over 90 %. F1 scores were also found to generally be over the optimal threshold of 0.8. The best results were obtained when detecting Actinic Keratosis, however differentiation between the two types of malignant lesions was often noted to be more difficult. These results demonstrate the potential of near-infrared hyperspectral imaging combined with advanced machine learning techniques in distinguishing NMSC from other skin lesions. Transfer learning was unsuccessful in improving the training of these algorithms.

CONCLUSIONS

We have shown that the Near-Infrared region of the electromagnetic spectrum is highly useful for the identification and study of non-melanoma type skin lesions. While the results are promising, further research is required to develop more robust algorithms that can minimize the impact of noise in these datasets before clinical application is feasible.

An Update on Non-Invasive Skin Imaging Techniques in Actinic Keratosis-A Narrative Review

Nonmelanocytic skin cancers (NMSCs) are currently the most common group of human cancers and include all tumors that are not melanomas. Increased exposure to sunlight over the past few years, the lack of regular and proper use of sunscreen, the aging of the population, and better screening techniques are the reasons for the escalation in their diagnosis. Squamous cell carcinoma (SCC) comprises nearly 37% of the tumors in this group and can originate from actinic keratosis (AK), which usually presents as pink, often scaly plaques, usually located on the face or scalp. Advances in dermatoscopy, as well as the development of other non-invasive skin imaging modalities such as high-frequency ultrasound (HFUS), reflectance confocal microscopy (RCM), and optical coherence tomography (OCT), have allowed for greatly increased sensitivity in diagnosing these lesions and monitoring their treatment. Since AK therapy is usually local, and SCCs must be removed surgically, non-invasive imaging methods enable to correctly qualify difficult lesions. This is especially important given that they are very often located on the face, and achieving an appropriate cosmetic result after treatments in this area is very important for the patients. In this review, the authors describe the use of non-invasive skin imaging methods in the diagnosis of actinic keratosis.

An overview of cutaneous squamous cell carcinoma imaging diagnosis methods

Cutaneous squamous cell carcinoma, a type of non-melanoma skin cancer, is a form of keratinocyte carcinoma that stands as one of the most prevalent cancers, exhibiting a rising frequency. This review provides an overview of the latest literature on imaging methods for diagnosing squamous cell carcinoma (SCC) and actinic keratosis (AK). It discusses the diagnostic criteria, advantages, and disadvantages of various techniques such as dermatoscopy, skin ultrasound (US), in vivo and ex-vivo reflectance confocal microscopy (RCM), and line-field confocal optical coherence tomography (LC-OCT). These methods offer benefits including non-invasiveness, rapidity, comprehensive lesion imaging, and enhanced sensitivity, but face challenges like high costs and the need for specialized expertise. Despite obstacles, the use of these innovative techniques is expected to increase with ongoing technological advancements, improving diagnosis and treatment planning for keratinocyte carcinomas. Standardizing LC-OCT imaging algorithms for AK, Bowen's disease, and SCC remains an area for further research.

Diagnosis of invasive cutaneous squamous cell carcinoma, imaging and staging

The assessment of patients with a lesion raising the suspicion of an invasive cutaneous squamous cell carcinoma (cSCC) is a frequent clinical scenario. The management of patients with cSCC is a multistep approach, starting with the correct diagnosis. The two main diagnostic goals are to differentiate from other possible diagnoses and correctly recognize the lesion as cSCC, and then to determine the tumor spread (perform staging), that is if the patient has a common primary cSCC or a locally advanced cSCC, or a metastatic cSCC (with in-transit, regional lymph nodal, or rarely distant metastasis). The multistep diagnostic approach begins with the clinical characteristics of the primary cSCC, it is complemented with features with dermoscopy and, if available, reflectance confocal microscopy and is confirmed with histopathology. The tumor spread is assessed by physical examination and, in some cases, ultrasound and/or computed tomography or magnetic resonance imaging, mainly to investigate for regional lymph node metastasis or for local infiltration into deeper structures. In the last step, the clinical, histologic and radiologic findings are incorporated into staging systems.

Cutaneous Squamous Cell Carcinoma: Clinico-Dermoscopic and Histological Correlation: About 72 Cases

INTRODUCTION

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer, accounting for 20% of malignant skin tumors. Dermoscopy is a very useful tool for diagnosing cSCC, and its findings are confirmed through histopathological studies.

OBJECTIVES

to describe the different dermoscopic structures of invasive cSCC and investigate their association with the clinical form and histopathological grade of differentiation.

METHODS

We conducted a cross-sectional study, collecting all patients diagnosed with squamous cell carcinoma over a period of 5 years. The study population was divided into two groups based on histological differentiation (well-differentiated and non-well-differentiated) and clinical form ( nodulo-ulcerative and nodular). Various dermoscopic parameters were compared between these groups.

RESULTS

Out of 72 invasive cSCC, 81.9% were well-differentiated, while 18.1% were non-well-differentiated. The clinical form of cSCC was nodulo-ulcerative in 83.3% of cases and nodular in 16.7%. Well-differentiated tumors showed dotted, glomerular and hairpin vessels, along with a predominant white pattern characterized by centrally distributed keratin as well as white circles, and whitish perivascular halo (P < 0.05). The distribution of these white structures was radial in nodulo-ulcerarive lesions, whereas in nodular lesions, their distribution, as well as that of keratin, was more diffuse (P < 0.05). Non-well-differentiated tumors showed a combined white-red pattern with the predominance of arborizing vessels (P < 0.05).

CONCLUSIONS

Our results show the reliability of dermoscopy as a tool for distinguishing between well- and poorly differentiated cSCC. This distinction is characterized by an increase in predominantly arborizing vessels and a corresponding decrease in white structures as the tumor progresses from a well-differentiated to a poorly differentiated state. Additionally, the nodulo-ulcerative form exhibits a central distribution of keratin, while the nodular form displays a diffuse distribution.

European consensus-based interdisciplinary guideline for invasive cutaneous squamous cell carcinoma. Part 1: Diagnostics and prevention-Update 2023

Invasive cutaneous squamous cell carcinoma (cSCC) is one of the most common cancers in white populations, accounting for 20% of all cutaneous malignancies. Overall, cSCC mostly has very good prognosis after treatment, with 5-year cure rates greater than 90%. Despite the overall favourable prognosis and the proportionally rare deaths, cSCC is associated with a high total number of deaths due to its high incidence. A collaboration of multidisciplinary experts from the European Association of Dermato-Oncology (EADO), the European Dermatology Forum (EDF), the European Society for Radiotherapy and Oncology (ESTRO), the European Union of Medical Specialists (UEMS), the European Academy of Dermatology and Venereology (EADV) and the European Organization of Research and Treatment of Cancer (EORTC), was formed to update recommendations on cSCC, based on current literature and expert consensus. Part 1 of the guidelines addresses the updates on classification, epidemiology, diagnosis, risk stratification, staging and prevention in immunocompetent as well as immunosuppressed patients.

The efficacy of dermoscopy in defining the surgical margins of cutaneous squamous cell carcinoma: a retrospective study

Objective

To investigate the diagnostic value of dermoscopy in defining the tumor margin of cutaneous squamous cell carcinoma (cSCC) for the appropriate surgical margin.

Methods

A total of 90 cSCC patients were enrolled in the study. All patients were recruited into two groups: those who preserved intact macroscopic features of neoplasms without or after incisional biopsy and those with uncertain residual tumors after excisional biopsy. A dermoscopy-defined surgical margin of 8mm outward was used according to the tumor boundaries observed with the naked eye and dermoscopy. All excised tumor specimens were divided into serial sections according to the four "3, 6, 9, 12" directions at every 4-mm interval from the dermoscopy-detected tumor margin. Pathological examination was performed at 0 mm, 4 mm, and 8 mm margins to confirm tumor remnants.

Results

Retrospective analysis of dermatoscopic results showed inconsistent clinical and dermatoscopic borders in 43 of 90 cases (47.8%). The ability of dermoscopy to detect tumor borders showed no statistical difference between the two groups (p > 0.05). In the unbiopsy or incisional biopsy group, 66.6% of the tumors were resected with a 4-mm margin and 98.3% with an 8-mm margin, with significant differences (p = 0.047). For patients with inconspicuous clinical evidence of residual tumor after excisional biopsy, the tumor clearance rate was 53.3% at 0 mm, 93.3% at 4 mm, and 100.0% at 8 mm. Statistically significant differences were noted between 0 mm and 4 mm (p = 0.017), as well as between 0 mm and 8 mm (p = 0.043) but did not differ between 4 mm and 8 mm (p > 0.05).

Conclusions

Dermoscopy defined the tumor margin of cSCC better than visual inspection alone. Direct dermoscopic-guided surgery with at least 8-mm expansion was recommended for high-risk cSCC. Dermoscopy also assisted in identifying surgical margins at the healing biopsy site, making 8 mm still the recommended expansion range.

The Multidisciplinary Management of Cutaneous Squamous Cell Carcinoma: A Comprehensive Review and Clinical Recommendations by a Panel of Experts

Cutaneous squamous cell carcinomas (CSCC) account for about 20% of all keratinocyte carcinomas, which are the most common form of cancer. Heterogeneity of treatments and low mortality are a challenge in obtaining accurate incidence data and consistent registration in cancer registries. Indeed, CSCC mostly presents as an indolent, low-risk lesion, with five-year cure rates greater than 90% after surgical excision, and only few tumors are associated with a high-risk of local or distant relapse; therefore, it is particularly relevant to identify high-risk lesions among all other low-risk CSCCs for the proper diagnostic and therapeutic management. Chemotherapy achieves mostly short-lived responses that do not lead to a curative effect and are associated with severe toxicities. Due to an etiopathogenesis largely relying on chronic UV radiation exposure, CSCC is among the tumors with the highest rate of somatic mutations, which are associated with increased response rates to immunotherapy. Thanks to such strong pre-clinical rationale, clinical trials led to the approval of anti-PD-1 cemiplimab by the FDA (Food and Drug Administration) and EMA (European Medicines Agency), and anti-PD-1 pembrolizumab by the FDA only. Here, we provide a literature review and clinical recommendations by a panel of experts regarding the diagnosis, treatment, and follow-up of CSCC.

Dermoscopy and ultrosound monitoring actinic keratosis with cutaneous squamous cell carcinoma: A case report and literature review

Actinic keratosis(AK) is a common premalignant skin lesion that can progress to invasive squamous cell carcinoma(iSCC). Clinically, AK presents as reddish or brownish macules, papules, or hyperkeratotic plaques. AK cannot be reliably predicted whether it will transform into invasive carcinomas, so skin biopsy is currently a gold standard for identifying suspicious malignancy. Currently, there are non-invasive methods to help diagnose and determine the difference between AKs and iSCC. For example, dermoscopy and ultrasound can be very useful in diagnosing and monitoring skin diseases non-invasively. Therefore, we report a case of multiple facial AKs with poorly differentiated skin squamous cell carcinoma, which was diagnosed early through dermoscopy and ultrasound, and confirmed by histopathology.

Malignant lesions of the ear

The dermatologic lesions of the external ear are quite protean and they encompass pre-malignant, malignant and inflammatory entities. The ear is endowed with functional and cosmetic importance and it is part of the "H-zone", which is the area of the head that generally presents tumors that can be considered high risk regardless of their size. As a matter of fact, skin malignancies of the ear tend to have a less benign course compared to the ones located on other areas of the body and complete excision has proven to be challenging. This mini-review provides an overview on the malignant cutaneous lesions of the external ear with a focus on their dermoscopic and reflectance confocal microscopy features. The most prevalent neoplasms of the auricle are squamous cell carcinoma and basal cell carcinoma followed by melanoma. These malignant lesions appear to be more common in men and to have a worse prognosis compared to when they arise from other body districts. There is a relative dearth of large studies centered on the clinical, dermoscopic and reflectance confocal microscopy features of skin cancers of the ear. Hence, further research inquiring into the specific dermoscopic and reflectance confocal microscopy characteristics of the cutaneous malignant lesions of the external ear, if any, are warranted for the future.

Clinical and dermatoscopic predictors of squamous cell carcinoma of the lips: a case-control, multicentric study

BACKGROUND

Squamous cell carcinoma of the lip accounts for 20% of all oral carcinomas. Its diagnosis may be challenging because it clinically resembles actinic cheilitis and inflammatory lesions of the lips.

OBJECTIVES

To determine clinical and dermatoscopic predictors of squamous cell carcinoma of the lip vs. other lip lesions.

METHODS

Multicentre retrospective morphological study, including histologically confirmed cases of squamous cell carcinoma of the lip and controls consisting of actinic cheilitis and inflammatory lesions of the lips. Clinical and dermatoscopic images were evaluated for the presence of predefined criteria. Crude and adjusted odds ratios and corresponding 95% confidence intervals were calculated by univariate and multivariate logistic regression respectively.

RESULTS

A total of 177 lip lesions were evaluated, 107 (60.5%) were squamous cell carcinomas and 70 (39.5%) were controls. The most frequent dermatoscopic criteria of lip squamous cell carcinoma were scales (100%), white halos (87.3%) and ulceration (79.4%). The majority of squamous cell carcinomas displayed polymorphic vessels (60.8%), with linear (68.6%) and hairpin (67.6%) being the most frequent types. Multivariate logistic regression analysis showed that clinical predictors of lip squamous cell carcinoma were exophytic appearance and clinical hyperkeratosis, with 43-fold and 6-fold higher probability respectively. White clods and ulceration in dermoscopy presented a 6-fold and 4-fold increased risk for squamous cell carcinoma respectively.

CONCLUSIONS

A scaly lesion with exophytic growth, dermatoscopically displaying white clods, ulceration and linear and hairpin vessels is very likely a squamous cell carcinoma of the lip.

Loss of DLX3 tumor suppressive function promotes progression of SCC through EGFR-ERBB2 pathway

Cutaneous squamous cell carcinoma (cSCC) ranks second in the frequency of all skin cancers. The balance between keratinocyte proliferation and differentiation is disrupted in the pathological development of cSCC. DLX3 is a homeobox transcription factor which plays pivotal roles in embryonic development and epidermal homeostasis. To investigate the impact of DLX3 expression on cSCC prognosis, we carried out clinicopathologic analysis of DLX3 expression which showed statistical correlation between tumors of higher pathologic grade and levels of DLX3 protein expression. Further, Kaplan-Meier survival curve analysis demonstrated that low DLX3 expression correlated with poor patient survival. To model the function of Dlx3 in skin tumorigenesis, a two-stage dimethylbenzanthracene (DMBA)/12-O-tetradecanoylphorbol 13-acetate (TPA) study was performed on mice genetically depleted of Dlx3 in skin epithelium (Dlx3cKO). Dlx3cKO mice developed significantly more tumors, with more rapid tumorigenesis compared to control mice. In Dlx3cKO mice treated only with DMBA, tumors developed after ~16 weeks suggesting that loss of Dlx3 has a tumor promoting effect. Whole transcriptome analysis of tumor and skin tissue from our mouse model revealed spontaneous activation of the EGFR-ERBB2 pathway in the absence of Dlx3. Together, our findings from human and mouse model system support a tumor suppressive function for DLX3 in skin and underscore the efficacy of therapeutic approaches that target EGFR-ERBB2 pathway.

Evaluation of dermatoscopic criteria for early detection of squamous cell carcinoma arising on an actinic keratosis

BACKGROUND

Advanced squamous cell carcinoma (SCC) can be discriminated easily from actinic keratosis (AK) based on clinical and dermatoscopic features. However, at the initial stage of dermal invasion, SCC might still be clinically flat and discrimination from AK remains challenging, even with the addition of dermatoscopy.

OBJECTIVE

The aim of this study was to investigate the clinical and dermatoscopic criteria that could suggest early invasion and serve as potent predictors to discriminate early SCC from AK.

METHODS

Clinical and dermatoscopic images of histopathologically diagnosed AKs and early SCCs were evaluated for the presence of predefined criteria by 3 independent investigators.

RESULTS

A total of 50 early SCCs and 45 AKs were included. The main positive dermatoscopic predictors of early SCC were dotted/glomerular vessels (odds ratio [OR] 3.83), hairpin vessels (OR 12.12), and white structureless areas (OR 3.58), whereas background erythema represented a negative SCC predictor (OR 0.22).

LIMITATIONS

The retrospective evaluation of images. Moreover, the differential diagnosis included in the study is restricted between AK and early SCC.

CONCLUSIONS

We identified potent predictors for the discrimination of AK and early SCC that may better guide management decisions in everyday clinical practice.

Dermoscopy as a Tool in Differentiating Cutaneous Squamous Cell Carcinoma From Its Variants

Background

Dermoscopic features of cutaneous squamous cell carcinoma (cSCC) have been widely studied, but their accuracy should be further investigated.

Objectives

This study assessed the diagnostic accuracy of a set of predetermined dermoscopic structures for 3 variants of cSCC, namely Bowen disease, keratoacanthoma and invasive cSCC.

Methods

Dermoscopic images of 56 histopathologically confirmed cSCC lesions (9 Bowen disease lesions, 7 keratoacanthomas, and 40 invasive cSCCs) were examined, and the diagnostic accuracy of dermoscopic structures was assessed. Discriminative ability of statistically significant positive predictors was determined using receiver operating characteristic (ROC) curves, and defined as an area under the ROC curve >0.700.

Results

Dermoscopic structures with statistical significance and discriminative ability were: for Bowen disease, clustered glomerular vessels and erosions; for keratoacanthoma, a central keratin plug; and for invasive cSCC, a mixed color of the background. Clustered and glomerular vessels had, for Bowen disease, perfect diagnostic accuracy, with: sensitivity of 88.9% for both features; specificity of 97.9% and 93.6%, respectively; positive predictive value (PPV) of 88.9% and 72.7%, respectively; and negative predictive value (NPV) of 97.8% for both. Erosions had, for BD, high specificity (87.2%) and NPV (91.1%), but low sensitivity (55.6%) and PPV (45.5%). A central keratin plug had, for keratoacanthoma, high specificity (87.8%) and NPV (93.5%), but low sensitivity (57.1%) and PPV (40%). A mixed background color had, for invasive cSCC, high specificity (81.3%) and PPV (89.7%), but low sensitivity (65%) and NPV (48.2%).

Conclusion

Dermoscopy accurately differentiates BD, through clustered glomerular vessels, from keratoacanthoma and invasive cSCC. Dermoscopic structures of keratoacanthoma and invasive cSCC overlap, and only histopathologic analysis differentiates them precisely.

Dermatoscopic findings and dermatopathological correlates in clinical variants of actinic keratosis, Bowen's disease, keratoacanthoma, and squamous cell carcinoma

Non-melanoma skin cancer (NMSC), predominantly squamous cell carcinoma (SCC) and basal cell carcinoma, is increasing worldwide. Dermatoscopy, which is one of the non-invasive diagnostic techniques, is important for early diagnosis of NMSC. In this study we aimed to determine dermatoscopic features of keratinocyte derived tumors including actinic keratosis (AK), Bowen's disease (BD), keratoacanthoma (KA), and SCC and correlate the dermatoscopic findings with pathology. A total of 242 lesions from 169 patients were included in the study and dermatoscopic and dermatopathological findings of the lesions were retrospectively studied. Revised pattern analysis was used for the dermatoscopic evaluation. Among 242 lesions, 145 were clinically flat (86 AK, 30 BD, and 29 SCC). Presence of vessels, ulceration, fiber sign, keratin mass, and blood spots decreased the probability of a lesion being AK. When the differential diagnosis was considered between KA and SCC vs AK and BD; vessel presence, ulceration, fiber sign, blood spots, white structureless, keratin, and centred vessels favored the diagnosis of KA and SCC. Our results may contribute to the determination of the lesions to be biopsied in patients with multiple AK on chronically sun damaged skin. In non-pigmented lesions when a final diagnosis cannot be established, knowledge of dermatopathologic and dermatoscopic correlation may significantly assist interpretation of dermatoscopic patterns and clues.

Cutaneous Squamous Cell Carcinoma: From Pathophysiology to Novel Therapeutic Approaches

Cutaneous squamous cell carcinoma (cSCC), a non-melanoma skin cancer, is a keratinocyte carcinoma representing one of the most common cancers with an increasing incidence. cSCC could be in situ (e.g., Bowen's disease) or an invasive form. A significant cSCC risk factor is advanced age, together with cumulative sun exposure, fair skin, prolonged immunosuppression, and previous skin cancer diagnoses. Although most cSCCs can be treated by surgery, a fraction of them recur and metastasize, leading to death. cSCC could arise de novo or be the result of a progression of the actinic keratosis, an in situ carcinoma. The multistage process of cSCC development and progression is characterized by mutations in the genes involved in epidermal homeostasis and by several alterations, such as epigenetic modifications, viral infections, or microenvironmental changes. Thus, cSCC development is a gradual process with several histological- and pathological-defined stages. Dermoscopy and reflectance confocal microscopy enhanced the diagnostic accuracy of cSCC. Surgical excision is the first-line treatment for invasive cSCC. Moreover, radiotherapy may be considered as a primary treatment in patients not candidates for surgery. Extensive studies of cSCC pathogenic mechanisms identified several pharmaceutical targets and allowed the development of new systemic therapies, including immunotherapy with immune checkpoint inhibitors, such as Cemiplimab, and epidermal growth factor receptor inhibitors for metastatic and locally advanced cSCC. Furthermore, the implementation of prevention measures has been useful in patient management.

Mucoscopy of lip squamous cell carcinoma and correlation with skin phototype and histological differentiation: a multicentric retrospective observational study by the International Dermoscopy Society

BACKGROUND

There is a scarcity of published data on the dermoscopic morphology of lip squamous cell carcinoma (SCC) and its variability according to the histological differentiation degree and patient's ethnicity as per skin phototype.

OBJECTIVES

To evaluate the dermoscopic features of SCC of the lips and identify possible dermoscopic clues that may aid in differentiation between well-differentiated, moderately-differentiated, and poorly-differentiated lesions, as well as between "fair" skin (Fitzpatrick skin phototypes I-III) and "dark" skin (Fitzpatrick skin phototypes IV-VI).

METHODS

The clinical profile and dermoscopic images of patients of any age and either gender with histologically confirmed lip SCC collated from seven dermatological centers were retrospectively evaluated for dermoscopic clues as per certain predefined criteria.

RESULTS

A total of 60 lesions from 60 patients were included in the analysis. Histologically, well, moderate, and poordifferentiation were seen in 24 (40%), 14 (23.3%), and 22 (36.7%) of the lesions, respectively. Other than the presence of brown-to-gray dots/globules, which was exclusively seen in cases with dark phototypes (19.4% P = 0.035), no other dermoscopic feature was statistically significant in differentiating between the two skin types. Some dermoscopic findings were observed specifically with statistical significance: perivascular white halos (P = 0.049) and whitish-yellow background in well-differentiated lesions (P = 0.003); pink background in moderately-differentiated lesions (P = 0.003); and red background with dense vascularity in poorly-differentiated lesions (P < 0.001).

CONCLUSIONS

The presence of vessels, scale/crust, and keratinization-associated white structures were the most common dermoscopic clues in lip SCC.

Early Squamous Cell Carcinoma With Perineural Invasion: A Prospective Study Examining Anatomic Site, Tumor Surface Diameter, Invasion Depth, and Grade of Differentiation in 1,772 Consecutive Cases

Background

Squamous cell carcinoma (SCC) may present with perineural invasion (PNI).

Objective

To investigate the characteristics of early invasive SCC with or without PNI.

Methods

Consecutive SCC excisions were prospectively reviewed from a single Australian community-based practice for 2016-2018. Tumor characteristics recorded were anatomic site, maximum microscopic tumor surface diameter, invasion depth, grade of differentiation, and diameter of nerves with PNI.

Results

In total, 1,772 cases were collected. No PNI cases were found on female patients. Seven of the total 10 PNI cases were on facial sites. Maximum average microscopic tumor surface diameters ranged from 10.1 mm (well differentiated) up to 11.0 mm (moderately differentiated). Maximum average invasion depths by differentiation ranged from 1.7 (well differentiated) up to 2.6 mm (poorly differentiated). The PNI cases were as follows: well differentiated (n = 0), moderately differentiated (n = 4), or poorly differentiated (n = 6). Minimum average histopathological margins for well, moderately, and poorly differentiated SCC, respectively, were 1.4, 1.1, and 1.3 mm. Minimum microscopic tumor surface diameters for PNI cases were 7 mm for moderately and 5 mm for poorly differentiated SCC. Minimum microscopic invasion depths for PNI cases were 2.2 mm for moderate and 0.9 mm for poor differentiation.

Conclusions

We found early SCC with PNI displayed nerve diameters of 0.1 mm or less and were exclusively on male patients aged 60 or older, on chronically sun-exposed sites of the head and upper midline anterior chest. Histopathological features associated with PNI were moderate and poor differentiation, tumor invasion beyond 0.9 mm, and adjacent lymphocytosis.

Proteomics: An emerging approach for the diagnosis and classification of cutaneous squamous cell carcinoma and its precursors

Cutaneous squamous cell carcinoma (cSCC) and its precursors, actinic keratosis (AK) and Bowen's disease (BD), are the most common types of keratinocytic skin lesions (KSL) which account for the majority of non-melanoma skin cancer lethality. Currently, clinical and histopathological criteria are used for the diagnosis, classification and therapeutic intervention of KSLs, however discrepancies exist between the clinical presentations and histologic analyses of these lesions, making the diagnosis difficult. The identification of biomarkers as companion diagnostics for accurately stratifying KSL types is required to support the paradigm shift in current cancer care to personalised, precision medicine and ameliorate the negative impact of misdiagnoses or delayed diagnoses on patient outcome. Also, it is essential to elaborate on the poorly defined molecular modifications required for the initiation, development and progression of KSL from normal keratinocytes. By harnessing recent technological advances in molecular profiling techniques, it is anticipated that greater insight into the various combinations of proteomic events or alternative pathways underlying carcinogenesis will be gained. This review will explore recent genomic studies in KSL followed by assessing the feasibility and significance of mass spectrometry-based proteomics profiling as a promising approach to a better understanding of the oncogenic pathways underpinning the formation and progression of KSL lesions and in aiding the identification of novel biomarkers and new therapeutic targets. The development of non-invasive tools such as tape-stripping coupled with proteomic analysis alone or in conjunction with imaging and genomic technologies will complement existing clinical and histopathological parameters, leading to an improvement in patient outcomes.

European interdisciplinary guideline on invasive squamous cell carcinoma of the skin: Part 1. epidemiology, diagnostics and prevention

Invasive cutaneous squamous cell carcinoma (cSCC) is one of the most common cancers in the white populations, accounting for 20% of all cutaneous malignancies. Factors implicated in cSCC etiopathogenesis include ultraviolet radiation exposure and chronic photoaging, age, male sex, immunosuppression, smoking and genetic factors. A collaboration of multidisciplinary experts from the European Dermatology Forum (EDF), the European Association of Dermato-Oncology (EADO) and the European Organisation of Research and Treatment of Cancer (EORTC) was formed to update recommendations on cSCC classification, diagnosis, risk stratification, staging and prevention, based on current literature, staging systems and expert consensus. Common cSCCs are typically indolent tumors, and most have a good prognosis with 5-year cure rates of greater than 90%, and a low rate of metastases (<4%). Further risk stratification into low-risk or high-risk common primary cSCC is recommended based on proposed high-risk factors. Advanced cSCC is classified as locally advanced (lacSCC), and metastatic (mcSCC) including locoregional metastatic or distant metastatic cSCC. Current systems used for staging include the American Joint Committee on Cancer (AJCC) 8th edition, the Union for International Cancer Control (UICC) 8th edition, and Brigham and Women's Hospital (BWH) system. Physical examination for all cSCCs should include total body skin examination and clinical palpation of lymph nodes, especially of the draining basins. Radiologic imaging such as ultrasound of the regional lymph nodes, magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography-computed tomography (PET-CT) scans are recommended for staging of high-risk cSCC. Sentinel lymph node biopsy is currently not recommended. Nicotinamide, oral retinoids, and topical 5-FU have been used for the chemoprevention of subsequent cSCCs in high-risk patients but are not routinely recommended. Education about sun protection measures including reducing sun exposure, use of protective clothing, regular use of sunscreens and avoidance of artificial tanning, is recommended.

Accuracy of dermoscopic criteria for the differential diagnosis between irritated seborrheic keratosis and squamous cell carcinoma

BACKGROUND

Even with the addition of dermoscopy, a significant morphologic overlap exists between irritated seborrheic keratosis (ISK) and squamous cell carcinoma (SCC).

OBJECTIVE

The aim of this study was to investigate the dermoscopic criteria that could serve as potent predictors for the differential diagnosis between ISK and SCC.

METHODS

Dermoscopic images of histopathologically diagnosed ISKs and SCCs were evaluated by 3 independent investigators for the presence of predefined criteria.

RESULTS

A total of 104 SCCs and 61 ISKs were included. The main dermoscopic predictors of SCC were dotted vessels (odds ratio [OR], 10.4), branched linear vessels (OR, 5.30), white structureless areas (OR, 6.78), white circles surrounding follicles (OR, 23.45), a diffuse irregular (OR, 2.55) or peripheral (OR, 2.8) vessel arrangement, and a central scale arrangement (OR, 3.35). Dermoscopic predictors of ISK were hairpin vessels (OR, 0.38), a diffuse regular vessel arrangement (OR, 0.39 and OR, 0.36), and white halos surrounding vessels covering more than 10% of the lesion (OR, 0.29 and OR, 0.12).

LIMITATIONS

First, the retrospective design of the study; second, the differential diagnosis included in the study was restricted to ISK and SCC.

CONCLUSIONS

We confirmed the significant morphologic overlap between ISK and SCC, but we also identified potent predictors for the differential diagnosis between these 2 entities.

Cutaneous keratinocyte cancers of the head and neck: Epidemiology, risk factors and clinical, dermoscopic and reflectance confocal microscopic features

Keratinocyte cancers are the most common malignancy among people with European ancestry, and are very common on sun-exposed areas of the head and neck. Incidence is directly correlated with latitude and annual ultraviolet radiation incidence, although there are a number of other environmental, occupational and genetic risk factors, and keratinocyte cancers become more common at middle age. Basal cell carcinomas (BCC) are the most common, comprising 80% of keratinocyte cancers, but have a very low rate of metastases and low mortality. Squamous cell carcinomas (SCC) make up 20% of keratinocyte cancers, and have relatively infrequent metastases, at 5-16%. While there are no precursor lesions for BCC, SCC represents the final stage in a spectrum of cellular atypia and dysplasia, from actinic keratoses to in situ SCC to invasive SCC. Dermoscopy is a well-established diagnostic tool for keratinocyte cancers, and reflectance confocal microscopy is emerging as another useful diagnostic tool, particularly on functionally and cosmetically sensitive sites like the face.

Dermoscopic Features of Lower Lip Squamous Cell Carcinoma: A Descriptive Study

Aim

Dermoscopic features of cutaneous squamous cell carcinoma (SCC) have been well described; however, there are a few studies focused on the dermoscopic aspect of lip SCC. In this study, we aimed to identify dermoscopic findings of lower lip SCC.

Materials and Methods

The clinical and histopathologic features, dermoscopic images, and demographic data of the patients with histologically approved lip SCC were retrospectively evaluated.

Results

A total of 10 lesions were enrolled in the study. Milky red structureless background (100%) and keratin scale (100%) were present in all the lesions. Blood spots on thick keratin scale were observed in eight lesions. Seven lesions showed white structureless areas. Two lesions exhibited ulceration and one of the lesions had structureless brown pigmentation. The most common vascular pattern observed was polymorphous vascular pattern (60%).

Conclusion

White and milky red structureless areas, blood spots on thick keratin scale, and polymorphous vascular pattern are the main dermoscopic clues to lip SCC. The presence of these findings should direct the clinician to the possibility of SCC. The dermoscopic findings observed may also reflect histological grade of the lesion.

Dermoscopy of Melanoma and Non-melanoma Skin Cancers

Dermoscopy is a widely used non-invasive technique for diagnosing skin tumors. In melanocytic tumors, e.g., melanoma and basal cell carcinoma (BCC), the effectiveness of dermoscopic examination has been fully established over the past two decades. Moreover, dermoscopy has been used to diagnose non-melanocytic tumors. Here, we review novel findings from recent reports concerning dermoscopy of melanoma and non-melanoma skin cancers including BCC, sebaceous carcinoma, actinic keratosis, Bowen's disease, squamous cell carcinoma (SCC), Merkel cell carcinoma (MCC), extramammary Paget's disease (EMPD), and angiosarcoma.

Poorly differentiated cutaneous squamous cell carcinomas have high incomplete excision rates with UK minimum recommended pre-determined surgical margins

BACKGROUND

In the UK, the British Association of Dermatology-British Association of Plastic, Reconstructive and Aesthetic Surgery (BAD-BAPRAS) guidelines recommend excision of high-risk cutaneous squamous cell carcinomas (cSCCs), including poorly differentiated cSCCs, with a minimum peripheral margin of 6 mm¹.

OBJECTIVES

We assess whether the BAD-BAPRAS minimum margin achieves histological clearance in poorly differentiated cSCCs.

PATIENTS AND METHODS

Demographics, surgical notes and histological reports from all patients having a primary cSCC excised at the Plastic Surgery Department of Addenbrooke's Hospital, Cambridge, UK, between January 2017 and April 2018 were analysed. Ordinal regression was performed for excision margin status versus histological grade by using size and site as co-variates.

RESULTS

Of 296 cSCCs, 38(12.8%) were poorly differentiated. Patients with poorly differentiated cSCCs were older (81.1 years vs. 76.7 years, p = 0.038), had lesions on the face or scalp (89.2% vs. 52.1%, p = 0.0001), and had lymphovascular (10.5% vs. 0%, p = 0.001) or perineural invasion (15.8% vs. 2%, p = 0.002). Well-differentiated cSCCs were excised with an average peripheral margin of 4.72 mm (95% CI 4.25-5.18 mm), while poorly differentiated cSCCs were excised with a margin of 6.42 mm(95% CI 5.58-7.28 mm). Close or involved peripheral margins were seen in 3% of well-differentiated lesions but in 13.2% of poorly differentiated lesions (OR=45.02; p = 0.003). Deep margins were close in 13.1% (none involved) of well-differentiated lesions but close or involved in 50% of poorly differentiated lesions (OR=11.94; p = 0.001).

CONCLUSIONS

We demonstrate that poorly differentiated cSCCs are frequently incompletely excised in both peripheral and deep planes, despite adherence to guidelines. The UK BAD-BAPRAS guidelines should be urgently updated in line with international consensus.

Investigational drugs currently in phase II clinical trials for actinic keratosis

INTRODUCTION

Actinic keratoses (AKs) are limited areas of irregular epidermal growth on a background of excessive solar exposure. The entire sun-damaged skin is considered a field of cancerization with multiple visible and subclinical lesions. AK management requires field-directed therapies to block lesion relapse and prevent squamous cell carcinoma (SCC).

AREAS COVERED

In this review, we focused on phase II clinical trials for AKs, involving well-known agents and newer molecules such as proapoptotic drugs (VDA-1102, SR-T100, oleogel-S10, ICVT, eflornithine), immunomodulants (isotretinoin, tretinoin) and chemopreventive agents (nicotinamide, perillyl alcohol, liposomal T4N5). We used the website 'ClinicalTrials.Gov' as main reference. We selected and discussed completed and ongoing trials and analysed chemical structure and mechanism of action of the investigated molecules.

EXPERT OPINION

AK therapy should be tailored on the patient's profile considering first of all the age and site of the AKs, which are relevant parameters for local immune response. The new molecules could be combined to obtain a synergic effect blocking the different steps of skin tumorigenesis. Phase II trials highlight a new therapeutic opportunity to block selectively cell proliferation regulators and work both on the field of cancerization and on the AKs currently present.

Early invasive squamous cell carcinoma recurrence rates: A study examining surgical margins, tumor surface diameter, invasion depth, and grade of differentiation in 1296 cases over 9 years

BACKGROUND

Invasive squamous cell carcinoma (SCC) is typically treated by surgical excision.

METHODS

Consecutive SCC excisions were reviewed prospectively in a single Australian center from 2009 to 2017. Cases were examined for recurrence by histopathologic margins, microscopic tumor surface diameter, invasion depth, grade of differentiation, and anatomic site.

RESULTS

Over 9 years, 1296 cases were collected. By grade of differentiation maximum average microscopic surface diameters ranged from 8.0 to 9.6 mm and maximum average depths from 1.3 to 2.5 mm. Minimum average histopathologic margins for well, moderate, and poorly differentiated SCC, respectively, were 1.4, 1.1, and 1.3 mm. Recurrence occurred in 1.7% of well (n = 18/1084), 1.8% moderate (n = 3/165) and 6.4% in poorly differentiated (n = 3/47) SCC. No recurrence occurred beyond a histopathologic margin of 3.5 mm for well and 2.5 mm for moderately differentiated SCC. Highest recurrence for well-differentiated SCC by anatomic site was the lip (7.0%) then ear (4.6%).

CONCLUSION

We found a recurrence rate of 1.0% for histopathologic margins of 1.5 mm with early well-differentiated SCC. The grade of differentiation and anatomic site had a larger influence on recurrence rates compared to the histopathologic margins. Poorly differentiated SCC and ear or lip sites require wider surgical margins.

Usefulness of dermoscopy to improve the clinical and histopathologic diagnosis of skin cancers

Multiple studies have shown that dermoscopy increases the sensitivity and specificity for the detection of skin cancers compared with examination by the naked eye. Dermoscopy can also lead to the detection of thinner and smaller cancers. In addition, dermoscopy leads to the more precise selection of lesions requiring excision. In essence, dermoscopy helps clinicians differentiate benign from malignant lesions through the presence or absence of specific dermoscopic structures. Therefore, because most dermoscopic structures have direct histopathologic correlates, dermoscopy can allow the prediction of certain histologic findings present in skin cancers, thus helping select management and treatment options for select types of skin cancers. Visualizing dermoscopic structures in the ex vivo specimens can also be beneficial. It can improve the histologic diagnostic accuracy by targeted step-sectioning in areas of concern, which can be marked by the clinician before sending the specimen to the pathologist, or by the pathologist on the excised specimen in the laboratory. In addition, ex vivo dermoscopy can also be used to select tumor areas with genetic importance because some dermoscopic structures have been related to mutations with theragnostic relevance. In the second article in this continuing medical education series, we review the impact of dermoscopy on the diagnostic accuracy of skin cancer, how dermoscopy can affect the histopathologic examination, and which dermoscopic features may be more relevant in terms of histologic and genetic prediction.

Current developments in pharmacotherapy for actinic keratosis

INTRODUCTION

Actinic keratosis (AK) is a superficial squamous cell carcinoma (SCC) where chronic sun exposure playing central role in its pathogenesis. UVB causes direct damage to DNA, producing pyrimidine dimers, and suppressing the protective role of p53. The stepwise progression of AK, with increased expression of anti-apoptotic Bcl-2, favors progression to SCC. Moreover, the dermal response characterized by inflammation and mediated by prostaglandins is a critical component of tumorigenesis that promotes tumor growth, tissue invasion, angiogenesis and metastasis. Other risk factors are represented by age, gender, phototype and drugs.

AREAS COVERED

In this review, the authors document the recent developments of different therapies used to treat AK and provide their perspectives on current and future treatment strategies.

EXPERT OPINION

The usefulness of long-term treatment with piroxicam and sun filters or diclofenac targeting the inflammation phases of skin tumorigenesis favors AK's healing and provides greater control of the cancerization field. Nonsteroidal anti-inflammatory drugs can be safely used in patients who use photosensitizing drugs and, therefore, are more at risk of developing skin tumors. Immunomodulatory therapies, which require shorter treatment, are characterized by more common local side effects, and need more attention by the dermatologist in the concern of patient education, resulting essential to improve adherence and outcomes.

Dermatoscopy of Neoplastic Skin Lesions: Recent Advances, Updates, and Revisions

OPINION STATEMENT

Dermatoscopy (dermoscopy) improves the diagnosis of benign and malignant cutaneous neoplasms in comparison with examination with the unaided eye and should be used routinely for all pigmented and non-pigmented cutaneous neoplasms. It is especially useful for the early stage of melanoma when melanoma-specific criteria are invisible to the unaided eye. Preselection by the unaided eye is therefore not recommended. The increased availability of polarized dermatoscopes, and the extended use of dermatoscopy in non-pigmented lesions led to the discovery of new criteria, and we recommend that lesions should be examined with polarized and non-polarized dermatoscopy. The "chaos and clues algorithm" is a good starting point for beginners because it is easy to use, accurate, and it works for all types of pigmented lesions not only for those melanocytic. Physicians, who use dermatoscopy routinely, should be aware of new clues for acral melanomas, nail matrix melanomas, melanoma in situ, and nodular melanoma. Dermatoscopy should also be used to distinguish between different subtypes of basal cell carcinoma and to discriminate highly from poorly differentiated squamous cell carcinomas to optimize therapy and management of non-melanoma skin cancer. One of the most exciting areas of research is the use of dermatoscopic images for machine learning and automated diagnosis. Convolutional neural networks trained with dermatoscopic images are able to diagnose pigmented lesions with the same accuracy as human experts. We humans should not be afraid of this new and exciting development because it will most likely lead to a peaceful and fruitful coexistence of human experts and decision support systems.

Cutaneous toxicities of new treatments for melanoma

New drugs against advanced melanoma have emerged during last decade. Target therapy and immunotherapy have changed the management of patients with metastatic disease. Along with its generalized use, drug toxicities have appeared and the skin is the target organ of a significant part of them. This revision summarizes the most common side effects and consensus management to improve the compliance of therapies and patients' quality of life. Among the BRAF inhibitors, main cutaneous side effects are photosensitivity, plantar hyperkeratosis, and the appearance of verrucal keratosis or squamous cell carcinoma. Special attention must be paid to the development of new primary melanomas or changes on nevi during BRAF inhibitor therapy. The most common cutaneous side effects of immunotherapy are rash, pruritus, and vitiligo. It remains controversial the possible role of these toxicities as markers of response to therapy.

Ex vivo confocal microscopy features of cutaneous squamous cell carcinoma

BACKGROUND

Rapid microscopic evaluation of cutaneous squamous cell carcinoma (SCC), its grade of differentiation and level of invasiveness would enable better management of patients' therapy.

OBJECTIVES

Analyzing specific ex vivo confocal microscopy criteria whether they can predict diagnosis of invasive SCC vs carcinoma in situ and poorly differentiated or undifferentiated vs well and moderately differentiated SCC.

METHODS

Ex vivo confocal images of 102 SCCs in 57 patients were evaluated immediately after excision for the presence of predefined criteria based on confocal and histological knowledge.

RESULTS

In histopathological examination, 30 SCCs were in situ and 72 invasive. Of these, 29 invasive SCC tumors were well, 19 moderately, 15 poorly differentiated and 9 undifferentiated. χ² analysis demonstrated that presence of erosion/ulceration, plump bright or speckled cells in dermis, keratin pearls and peritumoral inflammatory infiltrate correlated with diagnosis of invasive SCC. Erosion/ulceration and peritumoral inflammatory infiltrate were observed more frequently in poorly differentiated or undifferentiated tumors. Plump bright or speckled cells in the dermis were observed less often in well-differentiated tumors. The presence of keratin pearls was associated with well or moderately differentiated tumors.

CONCLUSION

Ex vivo CLSM allowed rapid examination of SCC and provided useful information on invasiveness and grading of the tumor.

Dermoscopy features of atypical fibroxanthoma: A multicenter study of the International Dermoscopy Society

BACKGROUND/OBJECTIVES

Little is known about the dermoscopic features of atypical fibroxanthoma.

METHODS

This was a case-control study. Atypical fibroxanthoma lesions were compared with a control group with non-melanoma skin cancer.

RESULTS

Altogether 40 atypical fibroxanthoma were collected. Most developed in men (93%), appearing mainly as nodular (63%), amelanotic (93%) and ulcerated (78%) lesions. Most lesions were located on the scalp (55%) and the ears (13%). Dermoscopically, most atypical fibroxanthoma displayed red (83%) and white (70%) structureless areas and irregular linear vessels (43%). A series of features achieved statistical significance when comparing atypical fibroxanthoma with non-melanoma skin cancer. The presence of red and white structureless areas and white lines, and the absence of yellowish-white opaque scales, hairpin vessels and arborising vessels were predictive of atypical fibroxanthoma in univariate analysis. However, when squamous cell carcinoma was excluded from the analysis, none of the criteria achieved statistical significance. When basal cell carcinoma was excluded, three variables achieved statistical significance in predicting atypical fibroxanthoma: red, structureless areas, the absence of opaque yellowish-white scales and absence of white circles.

CONCLUSIONS

Atypical fibroxanthomas seem to be barely distinguishable from basal cell carcinoma dermoscopically, but they are more easily distinguishable from a well to moderately differentiated squamous cell carcinoma. A histopathological examination is needed for the final diagnosis.

Suppression of skin tumorigenesis in CD109-deficient mice

CD109 is a glycosylphosphatidylinositol-anchored glycoprotein that is highly expressed in several types of human cancers, particularly squamous cell carcinomas. We previously reported that CD109-deficient mice exhibit epidermal hyperplasia and chronic skin inflammation. Although we found that CD109 regulates differentiation of keratinocytes in vivo, the function of CD109 in tumorigenesis remains unknown. In this study, we investigated the role of CD109 in skin tumorigenesis using a two-stage carcinogenesis model in CD109-deficient mice with chronic skin inflammation. Immunohistochemical analysis revealed a higher level of TGF-β protein expression in the dermis of CD109-deficient mice than in that of wild-type mice. Additionally, immunofluorescence analysis showed that Smad2 phosphorylation and Nrf2 expression were enhanced in primary keratinocytes from CD109-deficient mice compared with in those from wild-type mice. Although no significant difference was found in conversion rates from papilloma to carcinoma between wild-type and CD109-deficient mice in the carcinogenesis model, we observed fewer and smaller papillomas in CD109-deficient mice than in wild-type mice. Apoptosis and DNA damage marker levels were significantly reduced in CD109-deficient skin compared with in wild-type skin at 24 h after 7, 12-dimethylbenz (α) anthracene treatment. Furthermore, mutation-specific PCR revealed that the mutation frequency of the H-ras gene was less in CD109-deficient skin than in wild-type skin in this model. These results suggest that CD109 deficiency suppresses skin tumorigenesis by enhancing TGF-β/Smad/Nrf2 pathway activity and decreasing the mutation frequency of the H-ras gene.

The limitations of dermoscopy: false-positive and false-negative tumours

Dermoscopy has been documented to increase the diagnostic accuracy of clinicians evaluating skin tumours, improving their ability to detect skin cancer and better recognize benign moles. However, dermoscopically 'false-positive' and 'false-negative' tumours do exist. False-positive diagnosis usually leads to unnecessary excisions. False-negative diagnosis is much more dangerous, as it might result in overlooking a cancer, with severe undesirable consequences for the patient and the physician. Therefore, management strategies should mainly focus on addressing the risk of dermoscopically false-negative tumours. The most frequent benign tumours that might acquire dermatoscopic characteristics suggestive of malignancy are seborrhoeic keratosis (SK), including solar lentigo, melanoacanthoma, irritated, clonal and regressive SK, angioma (mainly thrombosed angioma and angiokeratoma), dermatofibroma, benign adnexal tumours and naevi (Clark, Spitz, recurrent, combined, sclerosing). The most useful clues to recognize these tumours are the following: solar lentigo - broad network; melanoacanthoma - sharp border; irritated SK - regularly distributed white perivascular halos; clonal SK - classic SK criteria; regressive SK - remnants of SK; targetoid haemosiderotic haemangioma - dark centre and reddish periphery; thrombosed angioma - sharp demarcation; angiokeratoma - dark lacunae; atypical dermatofibromas - palpation; follicular tumours - white colour; sebaceous tumours - yellow colour; Clark naevi - clinical context; Spitz/Reed naevi - age; combined naevi - blue central area; recurrent naevi - pigmentation within the scar; sclerosing naevi - age and location on the upper back; blue naevi - history. Malignant tumours that might mimic benign ones and escape detection are melanoma (in situ, nevoid, spitzoid, verrucous, regressive, amelanotic), squamous cell carcinoma (mainly well-differentiated variants) and rarely basal cell carcinoma (non-pigmented variants). The most useful clues to recognize the peculiar melanoma subtypes are as follows: melanoma in situ - irregular hyperpigmented areas; nevoid melanoma - history of growth; spitzoid melanoma - age; verrucous melanoma - blue-black sign; regressive melanoma - peppering or scar-like depigmentation; amelanotic melanoma - pink colour, linear irregular vessels, dotted vessels. In this article, we summarized the most frequent dermoscopic variations of common skin tumours that are often misinterpreted, aiming to assist clinicians to reduce the number of false diagnoses.

Invasive squamous cell carcinoma: comparison of differentiation grade and tumour depth by anatomical site in 1666 tumours

BACKGROUND

Invasive squamous cell carcinomas (SCCs) presents with different grades of differentiation and depths of invasion.

AIM

To compare the grade of differentiation, tumour diameter and tumour depth by anatomical site in invasive SCC.

METHODS

Retrospective clinical and histopathological data on consecutive cases of SCC came from a clinic in Sydney, Australia were assessed. A multinomial logistic regression model was applied to compare grades of differentiation by age, sex, anatomical sites, and histological tumour maximum diameter and depth.

RESULTS

In total, 1666 SCCs were identified, including 82.1% (n = 1367) well-differentiated, 13.3% (n = 222), moderately differentiated and 4.6% (n = 77) poorly differentiated SCCs. Patients with poorly differentiated tumours were more likely to be older and male (both P < 0.001). The most common site for poor differentiation was the scalp in men (n = 12; 15.6%) and the cheek or chin in women (n = 7; 9.1%). In the multivariate model, compared with well-differentiated SCC, older age was significantly associated with poorly and moderately differentiated SCC (P < 0.01 and P = 0.02, respectively). Larger tumour diameters were related to poor differentiation (P = 0.03). Ear, forehead and chest sites had increased tumour depth and poor differentiation.

CONCLUSIONS

This study found increased rates of poorly differentiated SCC on the forehead and cheek for both sexes, while men displayed increased rates of poorly differentiated SCC on the bald scalp and the ears. Tumour diameter and depth increased as tumours varied from well-differentiated to moderately differentiated and from moderately differentiated to poorly differentiated. An increase in depth and increased prevalence of poorly differentiated tumours were found on the ears for men and on various facial sites for both sexes.

Enhancing Skin Cancer Diagnosis with Dermoscopy

Dermoscopy increases the sensitivity for skin cancer detection, decreases the number of benign lesions biopsied for each malignant diagnosis, and enables the diagnosis of thinner melanomas compared with naked eye examination. Multiple meta-analyses have identified that dermoscopy improves the diagnostic accuracy for melanoma when compared with naked eye examination. In addition, studies have established that dermoscopy can aid in the detection of keratinocyte carcinomas. Dermoscopy triage algorithms have been developed to help novices decide when a biopsy or a referral is most appropriate. In this article, the authors illustrate the dermoscopic features that assist in identifying melanoma and keratinocyte carcinomas.

Dermoscopic and reflectance confocal microscopy features of cutaneous squamous cell carcinoma

BACKGROUND

Squamous cell carcinoma (SCC) of the skin is a highly prevalent neoplasm. The management and the prognosis of this tumour are dependent on its invasiveness and its grade of differentiation.

OBJECTIVES

To evaluate whether specific dermoscopic and reflectance confocal microscopy (RCM) criteria can predict the diagnosis of invasive SCC vs. in situ SCC and poorly differentiated compared with well- and moderately differentiated SCC.

METHODS

Dermoscopic and RCM images of SCC were retrospectively evaluated for the presence of predefined criteria.

RESULTS

Among 143 SCCs, 121 cases had a complete set of images and thus were included in the study set. The head and neck area was the most frequently involved body site (74/121; 61.1%) followed by extremities (36/121, 29.7%) and trunk (11/121, 9.1%). Seventy tumours were in situ (57.8%), while 51 were invasive (42.1%), of these 11 were poorly differentiated (21.5%), 16 were moderately differentiated (31.3%), and 24 were well differentiated (47.0%). Chi-squared analysis demonstrated that invasive SCCs were characterized by polymorphic vessels, erosion/ulceration, architectural disarrangement, speckled nucleated cells in the dermis, irregularly dilated vessels and absence of hyperkeratosis. Buttonhole vessels, white structureless areas and dotted or glomerular vessels were significantly associated with in situ lesions. Poorly differentiated SCCs were typified by red areas, erosion/ulceration and architectural disarrangement. Well- or moderately differentiated SCCs were associated with white areas and speckled nucleated cells in the epidermis.

CONCLUSION

Clinical, dermoscopic and RCM images provide useful information that should be integrated in order to achieve the optimal therapeutic management for the patient.

Dermoscopy of Malignant Skin Tumours: What's New?

Dermoscopy represents a new and effective tool that assists dermatologists in improving the accuracy of clinical diagnosis in onco-dermatology. The aim of this article is to provide an overview of the latest and important dermoscopic progress and observations in this ever-evolving field of dermatology.