Dermoscopy of Basal Cell Carcinoma Part 3: Differential Diagnosis, Treatment Monitoring and Novel Technologies

Introduction: Basal cell carcinoma (BCC) is the most frequently diagnosed skin cancer globally. Despite the well-established dermoscopic features of BCC, overlapping characteristics with other benign and malignant skin conditions cause challenges in differential diagnosis. Part III of this review highlights the role of dermoscopy in differential diagnosis, treatment planning, therapy monitoring and the integration of novel technologies including ultraviolet-induced fluorescence dermoscopy (UVFD) and optical super-high magnification dermoscopy (OSHMD). Methods: A search of the PubMed database was conducted for studies reporting on advances in the dermoscopic assessment of BCC, including differential diagnosis, treatment, monitoring and novel diagnostic technologies. Results: Even entities with well-defined dermoscopic features distinguishing them from BCC can sometimes mimic BCC. Additionally, rare lesions such as neurothekeoma, reticulohistiocytoma, solitary circumscribed neuroma, dermal leiomyosarcoma and various adnexal tumors often remain dermoscopically indistinguishable from BCC, which underscores the importance of histopathology as the diagnostic gold standard. Dermoscopy aids in delineating the tumor margins, optimizing Mohs micrographic surgery (MMS) and traditional excision. It may also help to monitor therapeutic effects by detecting the disappearance of BCC patterns, the presence of residual tumor or recurrences. Dermoscopy may aid in the prediction of therapeutic responses to imiquimod, photodynamic therapy or vismodegib. UVFD and OSHMD appear to be valuable complementary diagnostic techniques for detecting BCC. UVFD seems to be particularly valuable for the detection of small tumors (<5 mm), facial lesions and nodular or non-pigmented BCC subtypes, while OSHMD is useful for the assessment of superficial and non-pigmented BCCs. Three-dimensional total-body photography enhances diagnostic precision but, so far, only when used in combination with traditional dermoscopy. Conclusions: Dermoscopy is valuable for margin delineation, therapy monitoring and differential diagnosis but can be inconclusive, which highlights the role of histopathology as the gold standard. Modifications in dermoscopy technique may further enhance its accuracy.

Combined Carbon Dioxide Laser with Photodynamic Therapy for Nodular Basal Cell Carcinoma Monitored by Reflectance Confocal Microscopy

Introduction: Basal cell carcinoma (BCC) represents around 80% of all malignant skin cancers worldwide, constituting a substantial burden on healthcare systems. Due to excellent clearance rates (around 95%), surgery is the current gold-standard treatment. However, surgery is not always possible or preferred by patients. Numerous non-surgical therapies, sometimes combined, have been associated with promising tumor free survival rates (80-90%) in non-melanoma skin cancers (NMSCs). Most research has enrolled superficial basal cell carcinomas (sBCCs), with limited recent studies also involving low-risk nodular BCCs (nBCCs). Given lower efficacy rates compared to surgery, close monitoring during the follow-up period is essential for patients treated with non-surgical therapies. Monitoring with dermoscopy is constrained by low sensitivity rates. Reflectance confocal microscopy (RCM) is more sensitive in monitoring non-surgically treated NMSCs. Case presentation: A 41-year-old woman with a single nBCC relapse following photodynamic therapy (PDT) located on the dorsum of the nose presented to our center. Given the aesthetically sensitive location of the lesion and the patient's preference for a non-surgical approach, a combined treatment of CO2 laser and PDT was prescribed. A superpulsed CO2 laser (power: 0.5-3 W, frequency: 10 Hz, spot size 2 mm) with two PDT sessions (2 weeks apart) were conducted. At 6 weeks follow-up, monitoring performed with RCM revealed a reduction but not eradication of basaloid tumor islands. Another 2 sessions of PDT were recommended. At 3, 12 and 30 months of follow-up, the nasal dorsum area of the previous nBBC lesion was noted to be slightly hypopigmented (observed clinically), with a mild erythematous background (observed by dermoscopy). RCM evaluation confirmed the absence of RCM BCC criteria. The cosmetic outcome was very much improved. Conclusions: Combined CO2 laser and PDT for the treatment of a localized nBCC on the dorsum of the nose of a 41-year-old proved to offer tumor free survival at 30-month follow-up, as monitored with RCM. RCM is useful for the evaluation of non-surgical therapies as it has comparably higher sensitivity than dermoscopy and is especially useful in cases of suspected late recurrence. Further studies are needed to validate ongoing tumor free survival following this combined nonsurgical approach in the treatment of nBCC.

Reflectance Confocal Microscopy Follow-up of Multifocal Superficial Basal Cell Carcinomas Treated With Imiquimod 5% Cream

INTRODUCTION

Patients with multifocal superficial basal cell carcinomas (sBCC) require a non-invasive treatment and follow-up with a non-invasive technique. Imiquimod 5% cream is a new non-invasive therapy for BCC. Reflectance confocal microscopy (RCM) is a non-invasive, real-time imaging technique.

OBJECTIVES

To evaluate and describe the feasibility and efficacy of imiquimod 5% cream for the treatment of multifocal sBCC using RCM.

METHODS

The efficacy of imiquimod 5% cream for the treatment of multifocal sBCC was evaluated, as well as the potential of RCM for assessing therapeutic effects. We reported four patients with 34 sBCC lesions were treated with imiquimod 5% cream. RCM was performed in the baseline and at 12 weeks, 24 weeks and 52 weeks after starting treatment.

RESULTS

Of 34 lesions treated with imiquimod 5%, 32 responded to the treatment and showed complete clinical clearing. Two subclinical BCC lesions were identified by RCM. The complete tumor clearance rate was 88.2%, and the efficiency rate was 97.1%. No lesion recurred at 24-month follow-up. RCM identified previously described confocal features of BCC and was more sensitive than clinical examination. Local skin reactions were relieved after expectant treatment.

CONCLUSIONS

Imiquimod 5% cream may be useful for the treatment of multifocal sBCC, and its side effects are easy to manage. RCM can be used for non-invasive monitoring of treatment response and improved the tumor clearance rate.

Unusual Dermoscopic Patterns of Basal Cell Carcinoma Mimicking Melanoma

Background

Basal cell carcinoma can simulate melanoma and specific dermoscopic criteria have not yet been defined in a large cohort.

Objective

To identify dermoscopic “trump” characteristics for differential diagnosis, identify cluster groups and assess the clinical impact of this study's findings.

Methods

Retrospective, multicentric comparative study of atypical, non‐facial basal cell carcinoma (≥1 seven‐point checklist criteria) and melanoma (with at least one BCC criteria) at dermoscopy. Observed dermoscopic features were used to develop a proposed score. Lesion clusters were defined with hierarchical analysis. Clinical impact was assessed with a blinded reader study following this study's results.

Results

A total of 146 basal cell carcinoma and 76 melanoma were included. Atypical vascular pattern was common to most lesions (74.5%). Twelve trump features were included in the proposed score (sensitivity 94.1% and specificity 79.5%). Cluster analysis identified 3 basal cell carcinoma and 3 melanoma clusters. Findings improved overall diagnostic accuracy and confidence (26.8% and 13.8%, respectively; p < 0.001).

Conclusions

These findings support the notion that atypical vascular pattern should be considered a shared feature of both melanoma and atypical basal cell carcinoma. Our proposed score improves diagnostic accuracy and confidence. Absence of pigmented features was associated with lower diagnostic accuracy and confidence.

Line-field optical coherence tomography: In vivo diagnosis of basal cell carcinoma subtypes compared to histopathology

BACKGROUND

Basal cell carcinoma (BCC) is the most common skin cancer in the general population. Treatments vary from Mohs surgery to topical therapy, depending on the subtype. Dermoscopy, reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) have gained a foothold in daily clinical practice to optimize diagnosis and subtype-oriented treatment. The new device Line-field confocal OCT (LC-OCT) allows imaging at high resolution and depth but its use is not yet been investigated in larger studies.

OBJECTIVES

To evaluate the main LC-OCT criteria for the diagnosis and subtyping of BCC in comparison to histopathology, OCT and RCM.

METHODS

Fifty-two histopathologically confirmed BCCs were evaluated for imaging criteria. Their frequency, predictive values and ROC curves were calculated. A multinominal regression with stepwise variables selection to distinguish BCC subtypes was performed.

RESULTS

Nodular BCCs were mainly characterized by atypical keratinocytes, altered DEJ, tumour nests in the dermis, dark clefting, prominent vascularisation and white hyperreflective stroma. Superficial BCCs showed a thickening of the epidermis due to a series of tumour lobules with clear connection to the DEJ (string of pearls pattern). Infiltrative BCCs were characterized by elongated hyporeflective tumour strands, surrounded by bright collagen (shoal of fish). The overall BCC subtype agreement between LC-OCT and conventional histology was 90.4 % (95% CI: 79.0, 96.8).

CONCLUSION

LC-OCT allows the non-invasive, real time identification of BCCs and their subtypes in vertical, horizontal and 3D mode compared to histology, RCM and OCT. Further larger studies are needed to better explore the clinical applications of this promising device.

The effect of COVID-19 emergency in the management of melanoma in Italy

The COVID-19 pandemic has severely hampered the functioning of any health system, absorbing a considerable amount of resources and with the threat of widespread infection in the health services. The present survey has been carried out in Italy to evaluate if and how COVID-19 also affected skin melanoma management. We enrolled 13 Italian centres highly qualified in the diagnosis and care of skin melanoma. We compared a set of information evaluating the amount of activity for melanoma performed during February-April 2020 with the same quarter in 2019. The number of new melanoma diagnosis, biopsies, wide local excisions, overall pathology reports decreased. However, the most severe cases seem promptly managed with sentinel lymph node biopsies, new systemic treatments (north) and the total number of (advanced) treated patients (centre-south). The COVID-19 experience has underlined the need to exploit the help which may come from telemedicine.

Clinical Applications of In Vivo and Ex Vivo Confocal Microscopy

Confocal laser scanning microscopy (CLSM) has been introduced in clinical settings as a tool enabling a quasi-histologic view of a given tissue, without performing a biopsy. It has been applied to many fields of medicine mainly to the skin and to the analysis of skin cancers for both in vivo and ex vivo CLSM. In vivo CLSM involves reflectance mode, which is based on refractive index of cell structures serving as endogenous chromophores, reaching a depth of exploration of 200 μm. It has been proven to increase the diagnostic accuracy of skin cancers, both melanoma and non-melanoma. While histopathologic examination is the gold standard for diagnosis, in vivo CLSM alone and in addition to dermoscopy, contributes to the reduction of the number of excised lesions to exclude a melanoma, and to improve margin recognition in lentigo maligna, enabling tissue sparing for excisions. Ex vivo CLSM can be performed in reflectance and fluorescent mode. Fluorescence confocal microscopy is applied for “real-time” pathological examination of freshly excised specimens for diagnostic purposes and for the evaluation of margin clearance after excision in Mohs surgery. Further prospective interventional studies using CLSM might contribute to increase the knowledge about its application, reproducing real-life settings.

Clinical and Dermoscopic Factors for the Identification of Aggressive Histologic Subtypes of Basal Cell Carcinoma

Background

Infiltrative basal cell carcinoma (BCC) has a higher risk for post-surgical recurrence as compared to the most common low-aggressive superficial and nodular BCC. Independent diagnostic criteria for infiltrative BCC diagnosis have not been still defined. Improving the pre-surgical recognition of infiltrative BCC might significantly reduce the risk of incomplete excision and recurrence.

Objective

The aim of this study is to define clinical and dermoscopic criteria that can differentiate infiltrative BCC from the most common low-aggressive superficial and nodular BCC.

Methods

Clinical and dermoscopic images of infiltrative, superficial, and nodular BCC were retrospectively retrieved from our database and jointly evaluated by two experienced dermoscopists, blinded for the histologic subtype. Pairwise comparisons between the three histologic subtypes were performed and multivariable logistic regression models were constructed in order to define clinical and dermoscopic factors independently associated with each subtype. To validate our findings, two experienced dermoscopists not previously involved in the study were asked to evaluate clinical and dermoscopic images from an external dataset, guessing the proper BCC subtype between infiltrative, nodular and superficial, before and after being provided with the study results.

Result

A total of 481 histopathologically proven BCCs (51.4% nodular, 33.9% superficial, and 14.8% infiltrative) were included. We found that infiltrative BCC mostly appeared on the head and neck as an amelanotic hypopigmented plaque or papule, displaying ulceration on dermoscopic examination, along with arborizing and fine superficial telangiectasia. Shiny white structures were also frequently observed. Multivariate regression analysis allowed us to define a clinical-dermoscopic profile of infiltrative BCC.

Conclusions

We defined the clinical-dermoscopic profile of infiltrative BCC, allowing to differentiate this variant from superficial and nodular BCC. This will improve pre-surgical recognition of infiltrative forms, reducing the risk for post-surgical recurrence.

Dermoscopy in Basal Cell Carcinoma: An Updated Review

Dermoscopy is a noninvasive technique that has been demonstrated to improve diagnostic accuracy in basal cell carcinoma (BCC). The first dermoscopic model for the diagnosis of BCC, based mainly on the identification of pigmented structures, was described by Menzies et al., and since then dermoscopy has generated an abundance of literature useful to routine clinical practice. From a practical perspective, dermoscopic structures associated with BCC can be classified as pigmented, vascular, or nonpigmented/nonvascular. One of the most recent applications of dermoscopy in BCC is as an aid to predicting histologic subtype and essentially differentiating between superficial and nonsuperficial BCC. It can also, however, help raise suspicion of more aggressive variants with a higher risk of recurrence. A thorough dermoscopic examination during follow-up of patients with actinic damage or a history of multiple BCCs can facilitate the detection of very incipient lesions and significantly impact treatment and prognosis.

Long-term vemurafenib therapy in advanced melanoma patients: cutaneous toxicity and prognostic implications

BACKGROUND

The introduction of targeted therapies for the treatment of BRAF-mutated metastatic melanoma was associated with different cutaneous adverse events (AEs).

OBJECTIVES

To describe the type, frequency and severity of cutaneous AEs related to vemurafenib; to understand the association between AEs and vemurafenib efficacy in terms of median overall survival (OS) and median progression-free survival (PFS); to identify molecular characteristics of long-term responders.

METHODS

This observational, retrospective, monocentric study included all consecutive patients with unresectable stage III or stage IV melanoma and BRAF V600E mutation that started treatment with vemurafenib between May 2012 and May 2014.

RESULTS

62 patients with a median age of 56 years (range 26-82) were enrolled and received vemurafenib for a median period of 7.9 months (range 0.8-63.7). Among them, 45 patients presented at least one skin AE, 12 reduced the dosage due to cutaneous toxicity, and only one firstly reduced and after stopped the therapy. No specific molecular biomarkers were detected in long-term survivors.

CONCLUSIONS

Among long-term survivors, skin AEs seem to be less frequent and less severe. Results on multivariable analysis revealed that the presence of at least one G2 toxicity is a protective factor considering PFS, but not in terms of OS.

A brief synopsis on scalp melanoma

Melanoma constitutes one of the most sinister and troublesome malignancies encountered by humanity. Generally, the diagnosis of advanced melanoma connotes a grave prognosis, prompting a sense of looming threat of death, however, the early-stage detected disease responds well to robust treatment resulting in reasonable survivorship. Scalp melanomas are even more troublesome, because they typically exhibit more aggressive biologic behavior and are often diagnosed at a late stage. This review tries to comprehensively highlight the various diagnostic, therapeutic, and outcome aspects of scalp melanomas. The literature research includes peer-reviewed articles (clinical trials or scientific reviews). Studies were identified by searching electronic databases (MEDLINE and PubMed) till May 2020 and reference lists of respective articles. Only articles published in English language were included.

In Vivo Reflectance Confocal Microscopy in General Dermatology: How to Choose the Right Indication

Reflectance confocal microscopy (RCM) is a high-resolution, noninvasive imaging technique being increasingly used as an aid to diagnosis in the dermatology setting. RCM is applied in the diagnosis of both melanoma and nonmelanoma skin tumors, but also in the interpretation and management of inflammatory skin diseases. Two different devices with different designs for specific indications are available in the market: a static and a handheld probe. Several clinical presentations of the lesion could affect the examination, such as the presence of ulceration or hyperkeratosis; moreover, the anatomical site can drive the probe selection as well as the effective indication to RCM examination. In this review article, indications for the use of RCM are described in detail with a schematic approach for practical purposes.

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.

A Systematic Review and Meta-Analysis of the Accuracy of in VivoReflectance Confocal Microscopy for the Diagnosis of Primary Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most common cancer worldwide and its incidence is constantly rising. Early diagnosis and treatment can significantly reduce patient morbidity and healthcare costs. The value of reflectance confocal microscopy (RCM) in non-melanoma skin cancer diagnosis is still under debate. This systematic review and meta-analysis were conducted to assess the diagnostic accuracy of RCM in primary BCC. PubMed, Google Scholar, Scopus, and Web of Science databases were searched up to July 05, 2019, to collect articles concerning primary BCC diagnosis through RCM. The studies’ methodological quality was assessed by the QUADAS-2 tool. The meta-analysis was conducted using Stata 13.0, RevMan 5.0, and MetaDisc 1.4 software. We included 15 studies totaling a number of 4163 lesions. The pooled sensitivity and specificity were 0.92 (95% CI, 0.87–0.95; I² = 85.27%) and 0.93 (95% CI, 0.85–0.97; I² = 94.61%), the pooled positive and negative likelihood ratios were 13.51 (95% CI, 5.8–31.37; I² = 91.01%) and 0.08 (95% CI, 0.05–0.14; I² = 84.83%), and the pooled diagnostic odds ratio was 160.31 (95% CI, 64.73–397.02; I² = 71%). Despite the heterogeneity and risk of bias, this study demonstrates that RCM, through its high sensitivity and specificity, may have a significant clinical impact on the diagnosis of primary BCC.