The diagnostic accuracy of dermoscopy for basal cell carcinoma: A systematic review and meta-analysis

Importance of Both Clinical and Dermoscopic Findings in Predicting High-Risk Histopathological Subtype in Facial Basal Cell Carcinomas

INTRODUCTION

Being able to recognize high-risk facial basal cell carcinoma (BCC) may lead to fewer incomplete excisions and inappropriate treatments.

OBJECTIVES

We sought to investigate clinical and dermoscopic criteria for predicting facial BCC subtypes, analyze the interobserver agreement between readers, and develop a diagnostic algorithm to predict high-risk histopathological subtype.

METHODS

In this single-center, retrospective investigation, 6 independent readers evaluated predefined clinical and dermoscopic criteria in images of histopathologically verified primary facial BCCs including: topography, border demarcation, vessels, ulceration, white porcelain areas, shiny white blotches and strands, and pigmented structures and vessels within ulceration.

RESULTS

Overall, 297 clinical and dermoscopic image pairs were analyzed. The strongest associations with high-risk subtype were: "bumpy" topography (OR 3.8, 95% CI, 3.1-4.7), ill-defined borders (OR 3.4, 95% CI 3.1-4.7), white porcelain area (OR 3.5, 95% CI 2.8-4.5), and vessels within ulceration (OR 3.1, 95% CI 2.4-4.1). Predominantly focused vessels were a positive diagnostic criterium for either nodular (OR 1.7, 95% CI 1.3-2.2) or high-risk (OR 2.0, 95% CI 1.6-2.5) subtypes and a strong negative diagnostic criterium for superficial BCC (OR 14.0, 95% CI 9.6-20.8). Interobserver agreement ranged from fair to substantial (κ=0.36 to 0.72). A diagnostic algorithm based on these findings demonstrated a sensitivity of 81.4% (95% CI, 78.9-83.7%) and a specificity of 53.3% (95% CI, 49.7-56.9%) for predicting high-risk BCC subtype.

CONCLUSIONS

Integration of both clinical and dermoscopic features (including novel features such as topography and vessels within ulceration) are essential to improve subtype prediction of facial BCCs and management decisions.

Understanding the Dermoscopic Patterns of Basal Cell Carcinoma Using Line-Field Confocal Tomography

Basal cell carcinoma (BCC) is the most frequent malignancy in the general population. To date, dermoscopy is considered a key tool for the diagnosis of BCC; nevertheless, line-field confocal optical coherence tomography (LC-OCT), a new non-invasive optical technique, has become increasingly important in clinical practice, allowing for in vivo imaging at cellular resolution. The present study aimed to investigate the possible correlation between the dermoscopic features of BCC and their LC-OCT counterparts. In total, 100 histopathologically confirmed BCC cases were collected at the Dermatologic Clinic of the University of Siena, Italy. Predefined dermoscopic and LC-OCT criteria were retrospectively evaluated, and their frequencies were calculated. The mean (SD) age of our cohort was 65.46 (13.36) years. Overall, BCC lesions were mainly located on the head (49%), and they were predominantly dermoscopically pigmented (59%). Interestingly, all dermoscopic features considered had a statistically significant agreement with the LC-OCT criteria (all p < 0.05). In conclusion, our results showed that dermoscopic patterns may be associated with LC-OCT findings, potentially increasing accuracy in BCC diagnosis. However, further studies are needed in this field.

The effect of a dermoscopy training programme on diagnostic accuracy and management decisions regarding pigmented skin lesions: a comparison between dermal therapists and general practitioners

BACKGROUND

Dermoscopy is known to increase the diagnostic accuracy of pigmented skin lesions (PSLs) when used by trained professionals. The effect of dermoscopy training on the diagnostic ability of dermal therapists (DTs) has not been studied so far.

OBJECTIVES

This study aimed to investigate whether DTs, in comparison with general practitioners (GPs), benefited from a training programme including dermoscopy, in both their ability to differentiate between different forms of PSL and to assign the correct therapeutic strategy.

METHODS

In total, 24 DTs and 96 GPs attended a training programme on PSLs. Diagnostic skills as well as therapeutic strategy were assessed, prior to the training (pretest) and after the training (post-test) using clinical images alone, as well as after the addition of dermatoscopic images (integrated post-test). Bayesian hypothesis testing was used to determine statistical significance of differences between pretest, post-test and integrated post-test scores.

RESULTS

Both the DTs and the GPs demonstrated benefit from the training: at the integrated post-test, the median proportion of correctly diagnosed PSLs was 73% (range 30-90) for GPs and 63% (range 27-80) for DTs. A statistically significant difference between pretest results and integrated test results was seen, with a Bayes factor > 100. At 12 percentage points higher, the GPs outperformed DTs in the accuracy of detecting PSLs.

CONCLUSIONS

The study shows that a training programme focusing on PSLs while including dermoscopy positively impacts detection of PSLs by DTs and GPs. This training programme could form an integral part of the training of DTs in screening procedures, although additional research is needed.

Dermatoscopy and reflectance confocal microscopy for basal cell carcinoma diagnosis and diagnosis prediction score: A prospective and multicenter study on 1005 lesions

BACKGROUND

Basal cell carcinoma (BCC) is usually diagnosed by clinical and dermatoscopy examination, but diagnostic accuracy may be suboptimal. Reflectance confocal microscopy (RCM) imaging increases skin cancer diagnostic accuracy.

OBJECTIVE

To evaluate additional benefit in diagnostic accuracy of handheld RCM in a prospective controlled clinical setting.

METHODS

A prospective, multicenter study in 3 skin cancer reference centers in Italy enrolling consecutive lesions with clinical-dermatoscopic suspicion of BCC (ClinicalTrials.gov: NCT04789421).

RESULTS

A total of 1005 lesions were included, of which 474 histopathologically confirmed versus 531 diagnosed by clinical-dermatoscopic-RCM correlation, confirmed with 2 years of follow-up. Specifically, 740 were confirmed BCCs. Sensitivity and specificity for dermatoscopy alone was 93.2% (95% CI, 91.2-94.9) and 51.7% (95% CI, 45.5-57.9); positive predictive value was 84.4 (95% CI, 81.7-86.8) and negative predictive value 73.3 (95% CI, 66.3-79.5). Adjunctive RCM reported higher rates: 97.8 (95% CI, 96.5-98.8) sensitivity and 86.8 (95% CI, 82.1-90.6) specificity, with positive predictive value of 95.4 (95% CI, 93.6-96.8) and negative predictive value 93.5 (95% CI, 89.7-96.2).

LIMITATIONS

Study conducted in a single country.

CONCLUSIONS

Adjunctive handheld RCM assessment of lesions clinically suspicious for BCC permits higher diagnostic accuracy with minimal false negative lesions.

Dermoscopic Features of Pigmented Bowen Disease: A Multicenter Study on Behalf of the Ibero-Latin American College of Dermatology (CILAD)

INTRODUCTION

Studies focused on dermoscopic aspects of pigmented Bowen disease (pBD) in Latin American population are scarce and limited to only case reports or small series.

OBJECTIVES

To report dermoscopic findings in a large series of 147 pBD diagnosed in Ibero-Latin American population.

METHODS

We conducted a multicentric, retrospective study on 147 histologically proven pBD under the auspices of the Dermoscopy Chapter of the Ibero-Latin American College of Dermatology.

RESULTS

The study population consisted of 77 females (52%) and 70 males (48%) with a mean age of 68.6 years. 70.1% of patients had skin phototype 3, 15.6% to skin phototype 2, and 14.3% to skin phototype 4. On clinical examination, near 60% of pBD were flat, 70% presented with scales, and 90% were asymmetric. Under dermoscopy, structureless hypopigmented areas, dots brown and pink color were the most frequently observed. Regarding specific dermoscopic clues to pBD, the most prevalent were structureless hypopigmented areas, vessels arranged in linear fashion at the periphery, and pigmented lines or pigmented dots distributed in a linear fashion. Clustered, coiled, and dotted vessels were observed in 55.8%, 45.6%, and 45.6% of the cases, respectively.

CONCLUSIONS

We report a large series of cases of pBD in Latin American patients, with most patients being skin phototype 3 and 4. Distinctively in our study, the pigmented structures and the clues derived from the presence of melanin were much more frequent than in previous reports in fair skin.

Accuracy of an artificial intelligence as a medical device as part of a UK-based skin cancer teledermatology service

Introduction

An artificial intelligence as a medical device (AIaMD), built on convolutional neural networks, has demonstrated high sensitivity for melanoma. To be of clinical value, it needs to safely reduce referral rates. The primary objective of this study was to demonstrate that the AIaMD had a higher rate of correctly classifying lesions that did not need to be referred for biopsy or urgent face-to-face dermatologist review, compared to teledermatology standard of care (SoC), while achieving the same sensitivity to detect malignancy. Secondary endpoints included the sensitivity, specificity, positive and negative predictive values, and number needed to biopsy to identify one case of melanoma or squamous cell carcinoma (SCC) by both the AIaMD and SoC.

Methods

This prospective, single-centre, single-arm, masked, non-inferiority, adaptive, group sequential design trial recruited patients referred to a teledermatology cancer pathway (clinicaltrials.gov NCT04123678). Additional dermoscopic images of each suspicious lesion were taken using a smartphone with a dermoscopic lens attachment. The images were assessed independently by a consultant dermatologist and the AIaMD. The outputs were compared with the final histological or clinical diagnosis.

Results

A total of 700 patients with 867 lesions were recruited, of which 622 participants with 789 lesions were included in the per-protocol (PP) population. In total, 63.3% of PP participants were female; 89.0% identified as white, and the median age was 51 (range 18-95); and all Fitzpatrick skin types were represented including 25/622 (4.0%) type IV-VI skin. A total of 67 malignant lesions were identified, including 8 diagnosed as melanoma. The AIaMD sensitivity was set at 91 and 92.5%, to match the literature-defined clinician sensitivity (91.46%) as closely as possible. In both settings, the AIaMD identified had a significantly higher rate of identifying lesions that did not need a biopsy or urgent referral compared to SoC (p-value = 0.001) with comparable sensitivity for skin cancer.

Discussion

The AIaMD identified significantly more lesions that did not need to be referred for biopsy or urgent face-to-face dermatologist review, compared to teledermatologists. This has the potential to reduce the burden of unnecessary referrals when used as part of a teledermatology service.

Proposal of a new dermoscopic criterion for pigmented basal cell carcinoma: a multicentre retrospective study

Dermoscopy is widely used for the diagnosis of skin cancer and it increases the accuracy of basal cell carcinoma (BCC) detection. BCC dermoscopic criteria have been updated and divided into vascular, pigment-related, and non-vascular/non-pigment-related. Our multicenter retrospective study tested a new dermoscopic pigment-related characteristic to detect pigmented BCC (pBCC) [brown homogeneous blotches (BHB)]. Cases of pBCC were collected from the databases of IDI-IRCCS of Rome and from three Italian private dermatology centers. BHB are confined patches of brown uniform pigmentation without dermoscopic features (net, fat fingers, etc.) or other internal dermoscopic structures, except for occasional vascular ones like arborizing vessels or globules/dots. Melanocytic and non-melanocytic controls were used. We reviewed photos of 270 pigmented lesions (female 145; 51.8%), including 90 histopathologically verified pBCC and 180 control cases (90 melanocytic and 90 non-melanocytic). BHB were found in 61 cases of 90 pBCC patients. The results showed a 67.8 sensitivity, 93.3 specificity, 83.6 positive and 85.3 negative predictive values, posLR 10.2, negLR 0.3, odds ratio 29.4, p<0.001. Our multicentre retrospective analysis suggested the BHB may be a novel dermoscopic pBCC diagnosis criterion.

Basal Cell Carcinoma: Incidence and Trends in Valencia, Spain

BACKGROUND

There is a need for epidemiological and incidence data on the occurrence of basal cell carcinoma (BCC) in Spain.

OBJECTIVES

Our study was designed to retrospectively retrieve cases from our computer databases from 2010 through 2016 to provide updated data on the actual incidence of BCC in Valencia, eastern Spain.

MATERIAL AND METHODS

This was an epidemiological study on basal cell carcinoma conducted in Valencia, eastern Spain. We analyzed a total of 2171 patients and 4047 tumors, and gathered data to estimate the actual incidence of BBC in our region.

RESULTS AND CONCLUSIONS

Our study confirmed that the incidence of BCC is much higher than previously reported. We calculated a crude incidence of 410.38 BCCs/100 000 person-years, an adjusted rate for the European population of 256.98 BCCs/100 000 person-years, and an adjusted rate for the world population of 196.26 BCCs/100 000 person-years. Risk is up to 29.49% higher for men (464.07 cases/100 000 person-years vs 358.40 cases/100 000 person-years for women). Incidence also increases by an annual 3.91% (a significantly higher annual incidence of 8.28% in women vs a 0.92% annual incidence in men). Overall, the lifetime risk for developing a BCC is 5.8% (5.02% in women and 7% in men).

Comment on '"Poroma-like" branched vessels with rounded endings in dermoscopy of basal cell carcinoma: a new unusual structure'

This article advocates for the use of multiple noninvasive diagnostic tools for assessment and mutual validation to improve diagnostic accuracy in BCC. Different imaging techniques, each with its advantages, can provide multimodal preoperative information for management options that aim to meet the needs of clinicians.

Statistical evaluation and positive predictive value of key features of periorbital basal cell carcinoma

OBJECTIVE

To determine the accuracy of using the suspicious features of periorbital lesions-telangiectasias, madarosis, and ulceration-to identify basal cell carcinoma (BCC). This may impact whether a histopathologic confirmation is always necessary.

METHODS

This retrospective review of patients who underwent biopsy of eyelid lesions was conducted over a five-year period, between 2015 and 2020 at a single clinical site. Specifically, the histopathologic diagnosis and the presence or absence of clinical signs of madarosis, ulceration and telangiectasia were recorded. The positive predictive value (PPV) for eyelid BCC and odds ratio of each of these clinical signs was calculated.

RESULTS

179 patients underwent incisional biopsies of eye lid lesions. Of the 79 patients with eyelid BCC, 96% had ulceration, 95% had madarosis, and 75% had telangiectasias over the lid lesion; this contrasted with the 3%, 4% and 6% respectively in the 100 patients with benign lid lesions. The PPV for eyelid BCC of ulceration was 95.0%, madarosis was 96.2% and telangiectasias was 90.8%. The presence of two or all three signs in a patient was strongly predictive of BCC (PPV=100%).

CONCLUSION

The presence of two or more suspicious features almost ensures the accuracy of the suspected diagnosis of a BCC. This suggests that biopsy of eyelid lesions before complete surgical excision that demonstrate several defining features may not be necessary in all cases. However, lesions that do not demonstrate multiple explicit features that indicate a malignancy will still require histopathologic confirmation.

The Role of Dermoscopy in Provider-to-Provider Store-and-Forward Dermatology eConsults: A Scoping Review of the Recent Literature

Purpose of Review

This scoping review maps recent literature on dermatology provider-to-provider asynchronous store-and-forward (SAF) electronic consult (eConsult) platforms with dermoscopy. It offers a descriptive overview, highlighting benefits and challenges.

Recent Findings

Incorporating dermoscopy into SAF eConsults improves diagnostic accuracy for benign and malignant skin neoplasms. Diagnostic and treatment concordance with traditional face-to-face (FTF) visits is high. SAF eConsults with dermoscopy enhance access to dermatological care by improving triage and reducing wait times for FTF visits. Pediatric patients benefit with improved evaluation of melanocytic and vascular growths. eConsult platforms with dermoscopy serve as a telementoring opportunity for clinicians interested in improving their dermoscopy skills.

Summary

Adding dermoscopy to SAF eConsults is valuable and results in improved diagnostic accuracy and reduced need for FTF visits. Implementation barriers can be overcome through collaboration between primary care and dermatology. Dermoscopy in SAF eConsults has significant potential for managing skin conditions and reducing the burden caused by unnecessary FTF visit and biopsies.

Dermoscopy of very small basal cell carcinoma (≤3mm)

BACKGROUND

Basal cell carcinoma (BCC) dermoscopy is key to lower the biopsy threshold of suspicious lesions. There is a scarcity of published data on the dermoscopy of very small BCC (≤3mm) and its differences from larger BCCs.

OBJECTIVE

To describe and compare dermoscopic features of BCCs measuring ≤3mm, with those from 3 to 10mm.

METHODS

An analytical cross-sectional study, included biopsy-proven BCCs that had dermoscopic photographic images, between January 2017 and December 2022 in a Skin Cancer Center in Medellín, Colombia. Demographic, clinic-pathological and dermoscopic features were compared between very small BCCs (vsBCCs) and a reference group.

RESULTS

A total of 326 BCCs in 196 patients were included, of whom 60% were male. The most common Fitzpatrick phototype was III. vsBCCs accounted for 25% of the lesions (81/326). Face and neck were the most frequent locations (53%), especially in very small tumors. The nodular type was more common in very small tumors than in larger lesions, the superficial type was less frequent, and aggressive types were equally prevalent in both groups. On dermoscopy, very small tumors were statistically more likely to present pigmented structures than reference lesions, especially blue-gray dots (67% vs. 54%), vessels were less frequent, particularly short-fine telangiectasias (SFT) (52% vs. 66%), as were other structures such as shiny white structures (SWS), ulceration, micro-erosions, and scales.

STUDY LIMITATIONS

Latin-American sample, lacks information on dark phototypes CONCLUSIONS: Pigmented structures, especially blue-gray dots, were most common in vsBCCs when compared to larger lesions; SFT, SWS and other findings were less prevalent.

European consensus-based interdisciplinary guideline for diagnosis and treatment of basal cell carcinoma-update 2023

Basal cell carcinoma (BCC) is the most common malignant tumour in white populations. Multidisciplinary experts from European Association of Dermato-Oncology (EADO), European Dermatology Forum, European Society for Radiotherapy and Oncology (ESTRO), Union Européenne des Médecins Spécialistes, and the European Academy of Dermatology and Venereology developed updated recommendations on diagnosis and treatment of BCC. BCCs were categorised into 'easy-to-treat' (common) and 'difficult-to-treat' according to the new EADO clinical classification. Diagnosis is based on clinico-dermatoscopic features, although histopathological confirmation is mandatory in equivocal lesions. The first-line treatment of BCC is complete surgery. Micrographically controlled surgery shall be offered in high-risk and recurrent BCC, and BCC located on critical anatomical sites. Topical therapies and destructive approaches can be considered in patients with low-risk superficial BCC. Photodynamic therapy is an effective treatment for superficial and low-risk nodular BCCs. Management of 'difficult-to-treat' BCCs should be discussed by a multidisciplinary tumour board. Hedgehog inhibitors (HHIs), vismodegib or sonidegib, should be offered to patients with locally advanced and metastatic BCC. Immunotherapy with anti-PD1 antibodies (cemiplimab) is a second-line treatment in patients with a progression of disease, contraindication, or intolerance to HHI therapy. Radiotherapy represents a valid alternative in patients who are not candidates for or decline surgery, especially elderly patients. Electrochemotherapy may be offered when surgery or radiotherapy is contraindicated. In Gorlin patients, regular skin examinations are required to diagnose and treat BCCs at an early stage. Long-term follow-up is recommended in patients with high-risk BCC, multiple BCCs, and Gorlin syndrome.

'Poroma-like' branched vessels with rounded endings in dermoscopy of basal cell carcinoma: a new unusual structure

We report the cases of three patients with basal cell carcinoma that showed branched vessels with rounded endings, a vascular pattern never described in basal cell carcinoma and previously associated with eccrine poroma. We also speculate about the meaning of this pattern and underline the importance of this atypical vascular presentation in the differential diagnosis of malignant melanoma.

Use of preoperative and perioperative ex vivo dermoscopy for precise mapping of margins for standard surgical excision of primary basal cell carcinoma

Background The utility of preoperative and perioperative dermoscopy in standard surgical excision for radical excision of primary basal cell carcinoma remain unexplored. Aims To evaluate the use of preoperative and perioperative dermoscopy for precise mapping of margins during standard surgical excision of primary basal cell carcinoma. Methods In this retrospective, observational study, 17 patients clinically diagnosed with various morphological subtypes of basal cell carcinoma were included. Data about previous history, clinical examination of lesions and regional lymph nodes and preoperative dermoscopy were retrieved. After standard surgical excision had been carried out as per mapping of lateral margins, all the excised surgical specimens were subjected to perioperative dermoscopy and later reconfirmed with histopathology. Results Seventeen patients with mean age of 60.82 ± 9.99 years and median disease duration of 14 months were analysed. Clinically, basal cell carcinomas were of pigmented superficial subtype [6 (35.3%)], followed by pigmented nodular [5 (29.4%)], nodulo-ulcerative [4 (23.5%)] and micro nodular [2 (11.8%)]. Mean extension of clinical margin after dermoscopy was 0.59 ± 0.52 mm. Mean pre-assessed depth of tumour and mean depth of tumour were 3.46 ± 0.89 mm and 3.49 ± 0.92 mm, respectively. No recurrence was reported. Frequently found pre-operative dermoscopic features were maple leaf like structures [6 (35%)], blue grey dots and globules [6 (35%)] and short fine telangiectasias [6 (35%)]. Commonly observed perioperative dermoscopic features were: (1) irregular band with brown-grey pigmentation of dots, globules, streaks and pseudopodia like extensions [3 (50%)]; (2) irregular band of pseudo granulomatous structureless vascular areas in psoriasiform pattern with diffuse white streaks in pseudopodia like manner [1 (50%)]; (3) irregular band of pseudo granulomatous structureless vascular areas in psoriasiform pattern with streaks of white pseudopodia like structureless areas [1 (50%)]. Limitation This was a single-centre study with a small sample size. Conclusion This study highlights significance of preoperative and perioperative dermoscopy for precise planning and radical excision of primary basal cell carcinoma by standard surgical excision.

Morphology of Vessels in Basal Cell Carcinoma in Optical Super-high Magnification Dermoscopy

Abstract is missing (Short communication)

Perifolliculitis mimicking basal cell carcinoma

We present a case of a periocular painless perifolliculitis clinically mimicking basal cell carcinoma (BCC), excised by margin-controlled excision. This case reminds readers that perifolliculitis as a response to rosacea can mimic BCC. The value of diagnostic biopsy and dermoscopy to support management planning and avoid unnecessary surgery is discussed.

Dermoscopic Pattern of Basal Cell Carcinoma in H- and Non-H-zones

INTRODUCTION

Basal cell carcinoma (BCC) localized in the H-zone, the region of fusion of embryonic masses, has been associated with a higher risk of deeper invasion and more frequent recurrence.

OBJECTIVES

The aim of the study was to compare dermoscopic features of BCC in H and non-H zone that may most appropriately characterize those two locations.

METHODS

Dermoscopy images of histopathologically confirmed BCCs from 120 patients were retro-spectively analyzed. Dermoscopy features of BCC in H- and non-H zone were described and a comparative study of the dermoscopic pattern of BCC between the two locations was performed.

RESULTS

Of 120 BCC cases included in this study, 41 (34.2%) were located in the H-zone. The most frequent histological type was nodular (51.3% in H- zone and 61.6 % in non-H-zone) followed by superficial (5.1% and 19.8 % in H and non-H-zone respectively).In dermoscopy, there was a higher prevalence of ulceration (73.2% versus 43.6%, P < 0.001) in H-zone and a lower prevalence of brown globules (26.8% versus 53.2%; P = 0.01), when compared with the non-H-zone.

CONCLUSIONS

Our results show that dermoscopic features of BCC on the face fulfill a typical pattern regardless of the region, except for the prevalence of the ulceration which is significantly more frequent in H-zone and the brown globules present significantly more often in the non-H-zone It can be hypothesized that H-zone might predispose to more aggressive course of BCC complicated by ulceration and consequently deeper tissue destruction.

Recurrence or de novo? Intradermal Basal Cell Carcinoma of the Scrotum: A Report of Two Cases

Basal cell carcinoma (BCC) is the most common cutaneous malignancy, usually occurring in sun-exposed areas. Although BCC in the scrotal region is uncommon, it carries a higher risk of metastasis than BCC at other sites. Here, we report two cases of BCC that developed in the scrotal region: Case 1 presented as a superficial nodule and Case 2 as a subcutaneous nodule. Histopathologically, both tumors lacked continuity with the surface epidermis and formed an intradermal nodule. In Case 1, BCC occurred for the first time and presumably developed de novo. Case 2 underwent excision of a scrotal BCC 5 years previously, and the histopathological diagnosis at that time was nodular BCC. However, when the original specimen was re-examined, it was determined that, although the tumor had been completely resected, part of the lesion had moved away from the nodular area to represent a micronodular phenotype, an aggressive BCC subtype. We hypothesized that partial evolution from a nodular to a micronodular phenotype may have contributed to the recurrence of BCC in Case 2.

Basal cell carcinoma: Epidemiological impact of clinical versus histopathological diagnosis

BACKGROUND

Low-risk basal cell carcinomas (BCCs) are to an increasing extent diagnosed by dermatologists through dermoscopic examination only and treated with non-surgical methods. Reports on increasing incidence as well as trends regarding subtypes, anatomical sites and differences related to gender are based solely on histopathologically verified tumours. How unreported clinically diagnosed BCCs affect the epidemiological data has not been sufficiently investigated.

OBJECTIVES

To analyse the tumour and patient characteristics of clinically diagnosed versus histopathologically confirmed primary BCCs and to make a gross estimate on how unreported BCCs could influence the total number of new cases.

METHODS

We retrospectively reviewed all primary BCCs diagnosed in 2016 at the Department of Dermatology, Sahlgrenska University Hospital in Gothenburg, Sweden. We also reviewed all histopathologically verified primary BCCs at the two largest pathology laboratories in Western Sweden during the same year to estimate the proportion of BCCs diagnosed by dermatologists.

RESULTS

In total, 2365 primary BCCs were diagnosed at our centre. More than half of these tumours were clinically diagnosed (55.8%). Superficial subtype (41.7%), location on the trunk (46.3%) and destructive treatment methods (60.0%) were most common. The reports from the two pathology laboratories showed that histopathologically verified BCCs (n = 5837) were more commonly of the infiltrative or nodular subtype and located in the head and neck area. Dermatologists managed 56.0% of them.

CONCLUSIONS

This study indicates that a substantial number of BCCs are not visualized in the official statistics which are solely based on reports from pathology laboratories. When taking clinically diagnosed tumours into account, truncal location and superficial subtype are more common than previously believed. Further, based on the regional calculations, the real burden of BCC in Sweden might be up to 70% higher than what is reported in official statistics.

Infrared Macrothermoscopy Patterns-A New Category of Dermoscopy

(1) Background: The authors developed a new non-invasive dermatological infrared macroimaging analysis technique (MacroIR) that evaluates microvascular, inflammatory, and metabolic changes that may be dermoscopy complimentary, by analyzing different skin and mucosal lesions in a combined way-naked eye, polarized light dermatoscopy (PLD), and MacroIR-and comparing results; (2) Methods: ten cases were evaluated using a smartphone coupled with a dermatoscope and a macro lens integrated far-infrared transducer into specific software to capture and organize high-resolution images in different electromagnetic spectra, and then analyzed by a dermatologist; (3) Results: It was possible to identify and compare structures found in two dermoscopic forms. Visual anatomical changes were correlated with MacroIR and aided skin surface dermatological analysis, presenting studied area microvascular, inflammatory, and metabolic data. All MacroIR images correlated with PLD, naked eye examination, and histopathological findings; (4) Conclusion: MacroIR and clinic dermatologist concordance rates were comparable for all dermatological conditions in this study. MacroIR imaging is a promising method that can improve dermatological diseases diagnosis. The observations are preliminary and require further evaluation in larger studies.

Diagnostic accuracy of dermoscopy for 934 basal cell carcinomas: A single-center retrospective study

Although the efficacy of dermoscopic diagnosis of basal cell carcinoma (BCC) has already been established, most studies have been conducted in Western countries. However, there are racial differences in the clinicopathological characteristics of BCC, highlighting the need for a survey among Asians. Herein, we aimed to investigate the diagnostic accuracy of dermoscopy in 934 Japanese patients with BCC and statistically analyze the clinicopathological factors affecting diagnostic accuracy. We analyzed 5093 skin lesions, including 934 BCCs that were diagnosed consecutively from 1998 to 2018. The sensitivity and specificity of dermoscopic diagnosis for BCC were calculated. The sensitivity and specificity of dermoscopic diagnosis were 92.2% and 96.0%, respectively. There were 73 false-negative cases of BCCs that were clinically diagnosed with other diseases. The most common incorrect clinical diagnosis was seborrheic keratosis (n = 18), followed by melanocytic nevus (n = 15). Multiple logistic regression analysis showed that sensitivity was significantly lower in BCCs located on the trunk and extremities, which showed low pigmentation (less than 10% of the lesion surface) and were diagnosed by a resident dermatologist. Experience of 3-6 months of 12 resident dermatologists revealed increased sensitivity. Dermoscopy is a reliable tool for the accurate diagnosis of BCC in Japanese individuals. Care should be taken when diagnosing BCCs of the trunk and extremities, and the less-pigmented subtype because of lower sensitivity. A certain amount of experience is required to improve the skills for dermoscopy.

The current clinical approach to difficult-to-treat basal cell carcinomas

INTRODUCTION

Basal cell carcinoma (BCC) is the most common malignant tumor in adult white populations. If BCCs are not treated for years, if they cause massive destruction of the surrounding tissues, if they are considered unresectable or not eligible for radiotherapy they become progressively 'locally advanced' (laBCC) or metastatic (mBCC). These tumors are defined as 'difficult-to-treat BCC.'

AREAS COVERED

A comprehensive search on PubMed was conducted to identify relevant literature about the several approved and recommended treatment options for the management of difficult-to-treat BCC published from January 2012 to July 2022. Surgical options, radiotherapy, hedgehog inhibitors, immunotherapy, and combined treatments are discussed. The keywords used were basal cell carcinoma; difficult-to-treat BCC; management of difficult-to-treat BCC; surgical therapy; radiotherapy; hedgehog inhibitors; immunotherapy.

EXPERT OPINION

Identifying the best approach to DTT BCCs is one of the main challenges for the dermato-oncologist. The introduction of HHI for the treatment of advanced BCCs has revolutionized the clinical management of DTT BCCs. The immune checkpoint inhibitor cemiplimab has been approved for the treatment of locally advanced or metastatic BCC refractory to HHI therapy or in patients intolerant to HHI therapy. Multidisciplinary teams (MDTs) play a key role in managing these complex patients.

Smartphone-based single snapshot spatial frequency domain imaging

We report a handheld, smartphone-based spatial frequency domain imaging device. We first examined the linear dynamic range of the smartphone camera sensor. We then calculated optical properties for a series of liquid phantoms with varying concentrations of nigrosin ink and Intralipid, demonstrating separation of absorption and scattering. The device was then tested on a human wrist, where optical properties and hemoglobin-based chromophores were calculated. Finally, we performed an arterial occlusion on a human hand and captured hemodynamics using our device. We hope to lay the foundation for an accessible SFDI device with mass-market appeal designed for dermatological and cosmetic applications.

Diagnostic accuracy of dermoscopy for onychomycosis: A systematic review

Background

Dermoscopy is a non-invasive adjuvant diagnostic tool that allows clinicians to visualize microscopic features of cutaneous disorders. Recent studies have demonstrated that dermoscopy can be used to diagnose onychomycosis. We performed this systematic review to identify the characteristic dermoscopic features of onychomycosis and understand their diagnostic utility.

Methods

We searched the Medline, Embase, Scopus, and Cochrane databases from conception until May 2021. Studies on the dermoscopic features of onychomycosis were screened. The exclusion criteria were as follows: fewer than 5 cases of onychomycosis, review articles, and studies including onychomycosis cases that were not mycologically verified. Studies on fungal melanonychia were analyzed separately. We adhered to the MOOSE guidelines. Independent data extraction was performed. Data were pooled using a random effects model to account for study heterogeneity. The primary outcome was the diagnostic accuracy of the dermoscopic features of onychomycosis. This was determined by pooling the sensitivity and specificity values of the dermoscopic features identified during the systematic review using the DerSimonian-Laird method. Meta-DiSc version 1.4 and Review Manager 5.4.1 were used to calculate these values.

Results

We analyzed 19 articles on 1693 cases of onychomycosis and 5 articles on 148 cases of fungal melanonychia. Commonly reported dermoscopic features of onychomycosis were spikes or spiked pattern (509, 30.1%), jagged or spiked edges or jagged edge with spikes (188, 11.1%), jagged proximal edge (175, 10.3%), subungual hyperkeratosis (131, 7.7%), ruins appearance, aspect or pattern (573, 33.8%), and longitudinal striae (929, 54.9%). Commonly reported features of fungal melanonychia included multicolor (101, 68.2%), non-longitudinal homogenous pigmentation (75, 50.7%) and longitudinal white or yellow streaks (52, 31.5%).

Conclusion

This study highlights the commonly identified dermoscopic features of onychomycosis. Recognizing such characteristic dermoscopic features of onychomycosis can assist clinicians diagnose onychomycosis by the bedside.

Syringocystadenoma Papilliferum and Basal Cell Carcinoma Arising in Nevus Sebaceous

Nevus sebaceous (NS) is a benign congenital hamartoma with the potential to develop into a secondary benign or malignant skin tumors. Two or more skin tumors rarely arise simultaneously from a single NS lesion. Herein, we report a case of syringocystadenoma papilliferum and basal cell carcinoma arising in an NS, based on dermoscopic, reflectance confocal microscopic, and histopathological findings.

Effect of Reflectance Confocal Microscopy for Suspect Lesions on Diagnostic Accuracy in Melanoma: A Randomized Clinical Trial

Importance

Previous systematic reviews and meta-analyses have concluded that given data paucity, a comparison of reflectance confocal microscopy (RCM) with dermoscopy is complex. They recommend comparative prospective studies in a real-world setting of suspect lesions.

Objective

To test the hypothesis that RCM reduces unnecessary lesion excision by more than 30% and identifies all melanoma lesions thicker than 0.5 mm at baseline.

Design, Setting, and Participants

This randomized clinical trial included 3165 patients enrolled from 3 dermatology referral centers in Italy between January 2017 and December 2019, with a mean (SD) follow-up of 9.6 (6.9) months (range, 1.9-37.0 months). The consecutive sample of 3165 suspect lesions determined through dermoscopy were eligible for inclusion (10 patients refused). Diagnostic analysis included 3078 patients (48 lost, 39 refused excision). Data were analyzed between April and September 2021.

Interventions

Patients were randomly assigned 1:1 to standard therapeutic care (clinical and dermoscopy evaluation) with or without adjunctive RCM. Information available guided prospective clinical decision-making (excision or follow-up).

Main Outcomes and Measures

Hypotheses were defined prior to study initiation. All lesions excised (baseline and follow-up) were registered, including histopathological diagnoses/no change at dermoscopy follow-up (with or without adjunctive RCM). Number needed to excise (total number of excised lesions/number of melanomas) and Breslow thickness of delayed diagnosed melanomas were calculated based on real-life, prospective, clinical decision-making.

Results

Among the 3165 participants, 1608 (50.8%) were male, and mean (SD) age was 49.3 (14.9) years. When compared with standard therapeutic care only, adjunctive RCM was associated with a higher positive predictive value (18.9 vs 33.3), lower benign to malignant ratio (3.7:1.0 vs 1.8:1.0), and a number needed to excise reduction of 43.4% (5.3 vs 3.0). All lesions (n = 15) with delayed melanoma diagnoses were thinner than 0.5 mm.

Conclusions and Relevance

This randomized clinical trial shows that adjunctive use of RCM for suspect lesions reduces unnecessary excisions and assures the removal of aggressive melanomas at baseline in a real-life, clinical decision-making application for referral centers with RCM.

Trial Registration

ClinicalTrials.gov Identifier: NCT04789421.

Dermatoscopically narrowed surgical margins for head and neck basal cell carcinoma: A retrospective case-control study

BACKGROUND

Basal cell carcinoma (BCC) can cause extensive tissue damage if untreated. Complete surgical excision is the treatment of choice, but especially in the head-and neck area, defining both radical and healthy skin sparing surgical margins is complex.

MATERIALS AND METHODS

Excised, small (≤ 1 cm), BCCs of the head and neck were retrospectively analyzed, comparing histological properness of surgical margins after clinical-dermatoscopical preoperative evaluation (cases), vs. clinical evaluation only (controls) and recurrences.

RESULTS

Of 281 BCCs: 6 % (8/139) of cases and 8 % (12/142) of controls had unproper deep margins; 4 % (5/139) of cases, 20 % (29/142) of controls had unproper lateral margins (P < 0.001). Surgical 3 mm lateral margins were unproper in 0 % (15/66) of cases, 15 % (10/66) of controls (P > 0.005); surgical 1-2 mm lateral margins were unproper in 7 % (5/73) of cases, 25 % (19/76) of controls (P < 0.01). Of cases excised at 3 mm, 1-2 mm, and controls, 1.5 %, 0 %, and 7.7 % recurred, respectively.

CONCLUSIONS

BCC excision at 3 mm may be appropriate in the head and neck for small, dermatoscopically well-defined and non-aggressive BCCs, attaining surgical cure rates of 100 % and 1.5 % recurrences. Excision at 1-2 mm should be reserved only for BCCs in very difficult-to-treat areas, as the surgical cure rate was only 93 %.

Dermatoskopisch kontrollierte, schmalere Resektionsränder bei Basalzellkarzinomen an Kopf und Hals: Retrospektive Fallkontrollstudie

Hintergrund: Unbehandelt kann das Basalzellkarzinom (BCC) erhebliche Gewebezerstörungen verursachen. Die komplette chirurgische Exzision ist die Behandlung der Wahl. Allerdings stellt es besonders im Gesichts- und Halsbereich eine Herausforderung dar, den Tumor vollständig zu entfernen und möglichst viel gesundes Gewebe zu erhalten. Material und Methoden: Bereits exzidierte kleine BCC (≤ 1 cm) von Kopf oder Hals wurden retrospektiv analysiert. Verglichen wurde die histologisch kontrolliert angemessene Breite des Resektionsrandes nach präoperativer dermatoskopischer Untersuchung (Fälle) im Vergleich zur rein klinischen Untersuchung (Kontrollen), sowie die Rezidivrate. Ergebnisse: Bei 281 BCC: 6 % (8/139) der Fälle und 8 % (12/142) der Kontrollen zeigten inadäquate basale Resektionsränder; 4 % (5/139) der Fälle und 20 % (29/142) der Kontrollen zeigten inadäquate laterale Resektionsränder (P < 0.001). Laterale Resektionsränder von 3 mm waren in 0 % (15/66) der Fälle, jedoch in 15 % (10/66) der Kontrollen inadäquat (P >0.005); laterale Resektionsränder von 1-2 mm waren in 7 % (5/73) der Fälle und in 25 % (19/76) der Kontrollen inadäquat (P < 0.01). Rezidive traten in den Fällen mit 3 mm Resektionsrand in 1,5 % auf, in den Fällen mit 1-2 mm Resektionsrand bei 0 %, und bei den Kontrollen bei 7,7 %. Schlussfolgerung: Für BCC im Kopf- und Halsbereich erscheint ein Resektionsrand von 3 mm angemessen, sofern das BCC klein, dermatoskopisch gut definiert und wenig aggressiv ist. Hier zeigten sich operative Heilungsraten von 100 % mit 1,5 % Rezidiven. Resektionsränder von 1-2 mm sollten nur für BCC in sehr schwierig zu behandelnden Bereichen in Betracht gezogen werden, da die Heilungsrate hier nur bei 93 % lag.

Curettage versus cryosurgery for superficial basal cell carcinoma: a prospective, randomised and controlled trial

Background

Basal cell carcinoma (BCC) is the most common cancer in the world and has a rising incidence. Current guidelines for low‐risk BCC including superficial BCC (sBCC) recommend several treatment options including destructive treatment methods, such as cryosurgery with or without prior curettage or curettage and electrodesiccation. Curettage only (i.e. without subsequent cryosurgery or electrodesiccation) is a simple and quick destructive treatment method used for many benign skin lesions but has not been sufficiently evaluated for the treatment of sBCCs.

Objectives

The objective was to compare the effectiveness of curettage vs. cryosurgery for sBCCs in terms of overall clinical clearance rates after 1 year as well as wound healing times.

Methods

A single‐centre non‐inferiority clinical trial was conducted. Non‐facial sBCCs with a diameter of 5–20 mm were randomised to either cryosurgery using one freeze–thaw cycle or curettage. At follow‐up visits, treatment areas were evaluated regarding the presence of residual tumour after 3–6 months and recurrence after 1 year. Further, wound healing times were assessed.

Results

In total, 228 sBCCs in 97 patients were included in the analysis. At 3–6 months, no residual tumours were seen in any of the treated areas. After 1 year, the clinical clearance rates for curettage and cryosurgery were 95.7% and 100%, respectively (P = 0.060). However, the non‐inferiority analysis was inconclusive. Wound healing times were shorter for curettage (4 weeks) compared to cryosurgery (5 weeks; P < 0.0001). Overall, patient satisfaction at 1 year was high.

Conclusions

Both treatment methods showed high clinical clearance rates after 1 year, whilst curettage reduced the wound healing time.

A systematic review of observational management of cutaneous basal cell carcinoma

BACKGROUND

Cutaneous basal cell carcinoma (BCC) is the commonest cancer in the United Kingdom and United States. Surgical excision is the most common treatment. This review summarises all published outcomes of observational/non-interventional management of cutaneous BCC.

METHODS

This PRISMA-compliant systematic review searched MEDLINE, EMBASE and CENTRAL databases from inception-June 2021. All studies reporting outcomes of observational management for BCC were included.

RESULTS

We identified 2529 titles, from which 4 full-text articles were eligible, reporting on 2298 individuals. Two studies were randomised controlled trials (RCTs) comparing histological clearance rates and adverse events following treatment with an inactive strategy (placebo cream) versus topical 5%-imiquimod (at different frequencies) for 6-12 weeks. Clearance rates ranged from 52-100% for imiquimod and 2-19% for placebo, with more adverse events associated with imiquimod. The other two studies used prospective cohort designs. One study assessed the natural history of BCCs managed expectantly in 39 individuals aged ≥80years. During the 15.8-month follow-up, 46.2% of lesions did not increase in size and 10.3% resolved. The remaining study compared treatment patterns of 1360 patients with non-melanoma skin cancer (NMSC) in individuals with or without limited life-expectancy (LLE). The LLE subgroup had a 5-year mortality rate of 43.3%, with no deaths attributed to NMSC. Only 3.3% of individuals with LLE underwent observational treatment. No study examined quality-of-life or cost-effectiveness.

CONCLUSION

There has been limited investigation of observational management of BCC, despite possible advantages of this strategy. Future RCTs should compare quality-of-life outcomes and utility-adjusted survival following interventional or observational management of BCC.

Adjunctive Diagnostic Methods for Skin Cancer Detection: A Review of Electrical Impedance-Based Techniques

Skin cancer is among the fastest-growing cancers with an excellent prognosis, if detected early. However, the current method of diagnosis by visual inspection has several disadvantages such as overlapping tumor characteristics, subjectivity, low sensitivity, and specificity. Hence, several adjunctive diagnostic techniques such as thermal imaging, optical imaging, ultrasonography, tape stripping methods, and electrical impedance imaging are employed along with visual inspection to improve the diagnosis. Electrical impedance-based skin cancer detection depends upon the variations in electrical impedance characteristics of the transformed cells. The information provided by this technique is fundamentally different from other adjunctive techniques and thus has good prospects. Depending on the stage, type, and location of skin cancer, various impedance-based devices have been developed. These devices when used as an adjunct to visual methods have increased the sensitivity and specificity of skin cancer detection up to 100% and 87%, respectively, thus demonstrating their potential to minimize unnecessary biopsies. In this review, the authors track the advancements and progress made in this technique for the detection of skin cancer, focusing mainly on the advantages and limitations in the clinical setting. © 2022 Bioelectromagnetics Society.

Diagnostic accuracy of basal cell carcinoma in dermatology setting in Serbia: A single-center study

Background/Aim. The growing incidence of skin tumors requires an accurate diagnosis. Dermoscopy, especially in vivo, enhances the diagnosis of basal cell carcinoma (BCC). Total body skin examination (TBSE), a visual inspection of the patient?s total body surface, is considered a basic step in the dermatological exam, especially in skin cancer screening. However, TBSE is still a matter of debate regarding its expediency in a real clinical setting. The aim of this study was to analyze the diagnostic accuracy of BCC detected and treated by referred dermatologists. Methods. The retrospective analysis included a five-year period of BCC detection during TBSE by visual inspection and dermoscopy. We calculated sensitivity, specificity and positive predictive value for BCC using histopathological results as the correct diagnosis. Results. Out of 3,346 biopsied skin tumors, 49.58% were malignant and 50.42% benign. The most common malignant tumor was BCC, accounting for 84.09%. Localization of BCCs was mainly on the trunk (38.92%) and the H-zone of the face (37.63%). Other localizations were face (non-H-zone) (6.67%), neck (3.01%), scalp (3.37%), arms (6.88%) and limbs (3.51%). Of all BCCs, 0.83% were recurrent BCC. The sensitivity for the diagnosis of BCC was 97.71%, and the positive predictive value was 95.08%. Conclusion. In the dermatology setting, TBSE and visual inspection with in vivo dermoscopy result in a very good diagnostic performance of BCC.

Basal cell carcinoma arising within a longstanding hemangioma

Basal cell carcinomas have been reported to arise within several different tumors. Without careful attention to detail, basal cell carcinomas may go unnoticed when presenting within or directly adjacent to another distinct tumor. The increased use and accessibility of dermoscopy has allowed dermatologists to detect skin cancers that might otherwise be undetected by the naked eye. This case report details a collision, detected by dermoscopy, of a basal cell carcinoma developing within a long-standing hemangioma (cherry angioma) on the left lower eyelid of a 75-year-old man.

Deep Learning for Basal Cell Carcinoma Detection for Reflectance Confocal Microscopy

Basal cell carcinoma (BCC) is the most common skin cancer, with over 2 million cases diagnosed annually in the United States. Conventionally, BCC is diagnosed by naked eye examination and dermoscopy. Suspicious lesions are either removed or biopsied for histopathological confirmation, thus lowering the specificity of noninvasive BCC diagnosis. Recently, reflectance confocal microscopy, a noninvasive diagnostic technique that can image skin lesions at cellular level resolution, has shown to improve specificity in BCC diagnosis and reduced the number needed to biopsy by 2-3 times. In this study, we developed and evaluated a deep learning-based artificial intelligence model to automatically detect BCC in reflectance confocal microscopy images. The proposed model achieved an area under the curve for the receiver operator characteristic curve of 89.7% (stack level) and 88.3% (lesion level), a performance on par with that of reflectance confocal microscopy experts. Furthermore, the model achieved an area under the curve of 86.1% on a held-out test set from international collaborators, demonstrating the reproducibility and generalizability of the proposed automated diagnostic approach. These results provide a clear indication that the clinical deployment of decision support systems for the detection of BCC in reflectance confocal microscopy images has the potential for optimizing the evaluation and diagnosis of patients with skin cancer.

Basal cell carcinoma: Comprehensive clinical and histopathological aspects, novel imaging tools and therapeutic approaches (Review)

Basal cell carcinoma (BCC) is one of the most common malignant tumors worldwide, involving the skin. It is also part of keratinocyte carcinomas, alongside its squamous counterpart. It has low mortality and extremely low metastatic rates (although when present, it indicates a poor patient prognosis); it also has a high morbidity rate through local destruction and recurrence, particularly when perineural invasion is observed, clinically or histopathologically. BCC development is the result of environmental and patient factors, with genetics and ultraviolet radiation playing major roles. The clinical and histopathological aspects vary according to tumor subtype, being classified as high-risk tumors (nodular, superficial, pigmented and infundibulocystic BCC with adnexal differentiation) and fibroepithelial subtypes, or as high-risk tumors (micronodular, infiltrating, sclerosing/morphoeic and basosquamous subtype or the type with sarcomatoid differentiation). Dermoscopy is now complimented by novel in vivo diagnostic tools (optical coherence tomography, reflectance confocal microscopy, high-resolution ultrasonography, Raman spectroscopy or terahertz pulse imaging), improving the diagnostic accuracy and providing tumor depth and lateral margins without the use of invasive techniques. Novel treatment approaches for the treatment of BCC have recently been investigated with the use of hedgehog pathway inhibitors, such as Vismodegib. These approaches aim for complete resolution, minimal side-effects, high patient satisfaction with the optimal cosmetic results, particularly in key areas, such as the face. The present review article summarizes and discusses the comprehensive clinical and histopathological aspects of BCC, and presents novel imaging tools and therapeutic approaches that have been identified.

Combined PARP1-targeted nuclear contrast and reflectance contrast enhances confocal microscopic detection of basal cell carcinoma

Reflectance confocal microscopy (RCM) with endogenous backscattered contrast can noninvasively image basal cell carcinomas (BCCs) in skin. However, BCCs present with high nuclear density and the relatively weak backscattering from nuclei impose a fundamental limit on contrast, detectability, and diagnostic accuracy. We investigated PARPi-FL, an exogenous nuclear poly (ADP-ribose) polymerase (PARP1)-targeted fluorescent contrast agent and fluorescence confocal microscopy (FCM) towards improving BCC diagnosis. Methods: We tested PARP1 expression in 95 BCC tissues using immunohistochemistry, followed by PARPi-FL staining in 32 fresh surgical BCC specimens. Diagnostic accuracy of PARPi-FL contrast was evaluated in 83 surgical specimens. Optimal parameters for trans-epidermal permeability of PARPi-FL through intact skin was tested ex vivo on 5 human skin specimens and in vivo in 3 adult Yorkshire pigs. Results: We found significantly higher PARP1 expression and PARPi-FL binding in BCCs, as compared to normal skin structures. Blinded reading of RCM-and-FCM images by two experts demonstrated a higher diagnostic accuracy for BCCs with combined fluorescence and reflectance contrast, as compared to RCM-alone. Optimal parameters (time and concentration) for PARPi-FL trans-epidermal permeation through intact skin were successfully determined. Conclusion: Combined fluorescence and reflectance contrast may improve noninvasive BCC diagnosis with confocal microscopy.

Role of Dermoscopy in the Assessment of Basal Cell Carcinoma

Basal cell carcinoma is one of the most common cancers in white people, with a continuous increase worldwide. Dermoscopy, a non-invasive technique, allows early diagnosis based on the presence of typical vascular structures, pigmented structures, and ulceration and the absence of specific melanocytic structures. Moreover, dermoscopy is useful in basal cell carcinoma management, enabling the differentiation between multiple histological subtypes, between pigmented and non-pigmented variants and allowing a more accurate assessment of surgical margins. After non-ablative therapies, dermoscopy allows the accurate detection of residual disease. The purpose of this review is to highlight the dermoscopic features encountered in basal cell carcinoma and to outline the role of dermoscopy for diagnosis and therapeutic response in this cancer.

Known and new facts on basal cell carcinoma

Basal cell carcinoma (BCC) is the most common malignant tumor in light‐skinned people and amounts to about 75 % of all cases of skin cancer. Increasing incidence rates have been reported for decades all over the world. The main risk factors include UV radiation, male sex, light skin type, advanced age, long‐term immunosuppression, a positive individual or family history, and certain genodermatoses. BCC metastasizes only rarely, and its mortality is low, but it is associated with significant morbidity. Genetic mutations especially in the hedgehog pathway play an important role in BCC pathogenesis. Non‐invasive procedures such as optical coherence tomography or confocal laser scan microscopy are increasingly utilized for diagnostics in addition to visual inspection and dermatoscopy, but only in exceptional cases can histological confirmation of the diagnosis be dispensed with. Various clinical and histological subtypes have been defined. Differentiating between BCC with high and low risk of recurrence has a significant influence on the choice of treatment. Most BCC can be treated effectively and safely with standard surgery, or in selected cases with topical treatment. Locally advanced and metastasized BCC must be treated with radiation or systemic therapy. Radiation is also an option for older patients with contraindications for surgery. The hedgehog inhibitors vismodegib and sonidegib are currently approved for systemic therapy of BCC in Europe. Approval for the PD1 inhibitor cemiplimab as second‐line therapy is expected in the near future.

Correlation between Autofluorescence Intensity and Histopathological Features in Non-Melanoma Skin Cancer: An Ex Vivo Study

Simple Summary

Non-melanoma skin cancers (NMSC) are the most prevalent neoplasms worldwide, especially in the Caucasian population. Radical surgical excision is considered the therapeutic gold standard, while incomplete tumor removal is invariably associated with recurrence and the need for reintervention. Autofluorescence (AF) spectroscopy has recently been investigated for early diagnosis of NMSC and assessment of tumor margins. Understanding changes in AF intensity in association with peculiar histological features could improve the diagnostic accuracy of skin fluorescence spectroscopy. The main goal of our work was to investigate the correlation between the intensity of cutaneous AF and the histopathological features of NMSC. The intensity of fluorescence emission in tissues obtained from NMSC samples was approximately 4 times lower than that in healthy conditions. In fact, mean AF intensity for BCC group was 4.5 and 4.4 for SCCs, with further variability being recorded according to histopathologic subtypes. Histopathological features such as hyperkeratosis, neoangiogenesis, fibrosis and elastosis are statistically associated with a decrease in AF intensity. Our data suggest that such tissue alterations could be responsible for the difference in AF emission between neoplastic and healthy tissue. These results support the potential application of AF as a useful non-invasive diagnostic tool for NMSCs.

Abstract

Non-melanoma skin cancer (NMSC) is the most common malignant tumor affecting fair-skinned people. Increasing incidence rates of NMSC have been reported worldwide, which is an important challenge in terms of public health management. Surgical excision with pre-operatively identified margins is one of the most common and effective treatment strategies. Incomplete tumor removal is associated with a very high risk of recurrence and re-excision. Biological tissues can absorb and re-emit specific light wave-lengths, detectable through spectrophotometric devices. Such a phenomenon is known as autofluorescence (AF). AF spectroscopy has been widely explored for non-invasive, early detection of NMSC as well as for evaluation of surgical margins before excision. Fluorescence-aided diagnosis is based on differences in spectral characteristics between healthy and neoplastic skin. Understanding the biological basis of such differences and correlating AF intensity to histological features could improve the diagnostic accuracy of skin fluorescence spectroscopy. The primary objective of the present pre-clinical ex vivo study is to investigate the correlation between the intensity of cutaneous AF and the histopathological features of NMSC. Ninety-eight lesions suggestive for NMSCs were radically excised from 75 patients (46 M; 29 F; mean age: 79 years). After removal, 115 specific reference points on lesions (“cases”; 59 on BBC, 53 on SCC and 3 on other lesions) and on peri-lesional healthy skin (controls; 115 healthy skin) were identified and marked through suture stitches. Such reference points were irradiated at 400–430 nm wavelength, and resulting emission AF spectra were acquired through spectrophotometry. For each case, AFIR (autofluorescence intensity ratio) was measured as the ratio between the number of photons emitted at a wavelength ranging between 450 and 700 nm (peak: 500 nm) in the healthy skin and that was captured in the pathological tissue. At the histological level, hyperkeratosis, neoangiogenesis, cellular atypia, epithelial thickening, fibrosis and elastosis were quantified by light microscopy and were assessed through a previously validated grading system. Statistical correlation between histologic variables and AFIR was calculated through linear regression. Spectrometric evaluation was performed on 230 (115 cases + 115 controls) reference points. The mean AFIR for BCC group was 4.5, while the mean AFIR for SCC group was 4.4 and the fluorescence peaks at 500 nm were approximately 4 times lower (hypo-fluorescent) in BCCs and in SCCs than in healthy skin. Histological variables significantly associated with alteration of AFIR were fibrosis and elastosis (p < 0.05), neoangiogenesis, hyperkeratosis and epithelial thickening. Cellular atypia was not significantly associated with alteration of AFIR. The intensity of fluorescence emission in neoplastic tissues was approximately 4 times lower than that in healthy tissues. Histopathological features such as hyperkeratosis, neoangiogenesis, fibrosis and elastosis are statistically associated with the decrease in AFIR. We hypothesize that such tissue alterations are among the possible biophysical and biochemical bases of difference in emission AF between neoplastic and healthy tissue. The results of the present evaluation highlighted the possible usefulness of autofluorescence as diagnostic, non-invasive and real-time tool for NMSCs.