Sensitivity and positive predictive values of presurgical clinical diagnosis of excised benign and malignant skin tumors: a prospective study of 835 lesions in 778 patients

Clinical Misdiagnosis of Cutaneous Malignant Tumors as Melanocytic Nevi or Seborrheic Keratosis: A Retrospective Analysis of a Chinese Population

Purpose

The rising incidence and mortality associated with cutaneous malignant tumours highlight the importance of early diagnosis of these tumors. In clinical practice, these tumors are often misdiagnosed as benign skin lesions such as melanocytic nevi (MN) and seborrheic keratosis (SK) because of their similar morphologic features. The incidence and clinicopathological subtypes of cutaneous malignancies in East Asia populations significantly differ from those in fair-skinned groups. However, studies on misdiagnoses in Eastern countries are lacking. Therefore, this study focused on the clinical and pathological features of cutaneous malignant tumors misdiagnosed as MN or SK in a Chinese population.

Patients and Methods

A total of 4592 samples clinically diagnosed as MN (n = 3503) or SK (n = 1089) from July 2014 to June 2022 were collected and evaluated retrospectively. The clinical and pathological data were analyzed to identify associated factors.

Results

Pathological assessments showed that 2.5% (86/3503) of the specimens clinically diagnosed as MN were malignancies, predominantly basal cell carcinoma (BCC, 84.9%, 73/86), followed by malignant melanoma (MM, 8.1%, 7/86) and squamous cell carcinoma (SCC, 7.0%, 6/86). Similarly, 5.7% (62/1089) of the specimens clinically diagnosed as SK were malignant tumors, of which BCC (50.0%, 31/62) was the most common, followed by SCC (41.9%, 26/62) and MM (8.1%, 5/62). In both types of specimens, advanced age and facial lesions were risk factors for malignancy misdiagnosis. The malignancy rate, mean age, and proportion of SCC in the specimens clinically diagnosed as SK were higher than those in the specimens clinically diagnosed as MN. Dermoscopy significantly reduced the rate of misdiagnosis of these tumors as MN or SK.

Conclusion

In China, cutaneous malignant tumors misdiagnosed as MN or SK are not uncommon in clinical practice, and active introduction of noninvasive diagnostic techniques is essential to distinguish them.

A Clinicopathological Study of Skin Tumors from a Tertiary Care Centre in North India

BACKGROUND

There is a huge spectrum of skin tumors which can be confused clinically with malignancies, particularly when they are pigmented or inflamed, and histopathological examination of a biopsy specimen is required to establish a definitive diagnosis and to facilitate appropriate intervention and follow up.

AIM

To evaluate all skin tumors and categorize them according to their origin.

METHODS

The present study was conducted over a period of 4 years (July 1, 2013 to June 31, 2017) comprising of 1.5 years prospective and 2.5 years retrospective analysis in the departments of Dermatology and Pathology, at a tertiary hospital in North India. All specimens of skin tumors were analyzed grossly and microscopically. Immunohistochemistry was done wherever possible.

RESULTS

A total of 232 skin tumors were seen; of which 123 cases were benign (53.0%) and 109 cases were malignant (47.0%). The mean age of patients with benign and malignant skin tumors was 40.3 ± 19.9 and 60.8 ± 14.8 years, respectively. The most common site was face (n = 106; 45.7%) followed by limbs (n = 44; 19.0%). The male:female ratio of benign and malignant tumors was 1.01:1 and 1.31:1, respectively. Among the benign tumors, keratinocytic tumors were the commonest (n = 57; 46.3%) followed by the melanocytic tumors (n = 37; 30.1%) and appendageal tumors (n = 29; 23.6%). The most common malignant skin tumors were the keratinocytic tumors (n = 87; 79.8%) followed by 12 cases (11%) of hematolymphoid tumors and five cases (4.6%) each of melanocytic and appendageal tumors.

LIMITATIONS

The lack of clinical and dermatoscopic correlation and inclusion of retrospective data are the limitations of this study.

CONCLUSIONS

Skin tumors affect people of all ages. The benign tumors are seen in the younger age group as compared to malignant tumors. Face is the most common site and keratinocytic tumors are the most common skin tumors in both benign and malignant categories.

Evaluation of the Number-Needed-to-Biopsy Metric for the Diagnosis of Cutaneous Melanoma: A Systematic Review and Meta-analysis

Importance

To date, no concerted effort has been made to date to evaluate the literature on number-needed-to-biopsy (NNB) metrics, particularly to account for the differences in clinician type and melanoma prevalence in certain geographic locations.

Objective

To review and synthesize worldwide data for NNB for the diagnosis of cutaneous melanoma.

Data Source

MEDLINE, Embase, and PubMed databases were searched for English-language articles published worldwide from January 1, 2000, to November 28, 2018.

Study Selection

A total of 46 studies were included that addressed NNB for at least 3681 clinicians worldwide and included 455 496 biopsied tumors and 29 257 melanomas; primary care practitioner (PCP) data were only available from Australia.

Data Extraction and Synthesis

Articles were screened for eligibility, and possible overlapping data sets were resolved. Data extracted included clinician specialization, use of dermoscopy, geographic region and location-specific health care system, study design, number of benign tumors, number of melanomas, and NNB. The review followed the PRISMA guidelines.

Main Outcome and Measures

The NNB for the diagnosis of cutaneous melanoma.

Results

A total of 46 studies were included that addressed NNB for at least 3681 clinicians worldwide and included 455 496 biopsied tumors and 29 257 melanomas; primary care practitioner (PCP) data were only available from Australia. The reported NNB ranged from 2.2 to 287, and the weighted mean NNB for all included publications was 15.6. The exclusion of publications structured as all biopsied tumors, owing to variable data characterization, resulted in reported NNB ranging from 2.2 to 30.5, with a global weighted mean NNB of 14.8 for all clinicians, 7.5 for all dermatologists, 14.6 for Australian PCPs, and 13.2 for all US-based dermatological practitioners, including dermatologists and advanced practice professionals. The summary effect size (ES) demonstrates that a mean 4% of biopsies demonstrated melanoma for study stratum A (all biopsied skin tumors, ES, 0.04; 95% CI, 0.03-0.05), and a mean 12% of biopsies demonstrated melanoma for study strata B (melanocytic tumors on pathology review, ES, 0.12; 95% CI, 0.10-0.14) and C (clinical concern for melanoma, ES; 0.12; 95% CI, 0.09-0.14).

Conclusions and Relevance

The existing NNB for cutaneous melanoma appeared to vary widely worldwide, lacking standardization in the metric and its reporting, and according to clinician characteristics as well; the NNB of US-based clinicians may warrant further exploration.

Visual inspection for diagnosing cutaneous melanoma in adults

BACKGROUND

Melanoma has one of the fastest rising incidence rates of any cancer. It accounts for a small percentage of skin cancer cases but is responsible for the majority of skin cancer deaths. History-taking and visual inspection of a suspicious lesion by a clinician is usually the first in a series of 'tests' to diagnose skin cancer. Establishing the accuracy of visual inspection alone is critical to understating the potential contribution of additional tests to assist in the diagnosis of melanoma.

OBJECTIVES

To determine the diagnostic accuracy of visual inspection for the detection of cutaneous invasive melanoma and atypical intraepidermal melanocytic variants in adults with limited prior testing and in those referred for further evaluation of a suspicious lesion. Studies were separated according to whether the diagnosis was recorded face-to-face (in-person) or based on remote (image-based) assessment.

SEARCH METHODS

We undertook a comprehensive search of the following databases from inception up to August 2016: CENTRAL; CINAHL; CPCI; Zetoc; Science Citation Index; US National Institutes of Health Ongoing Trials Register; NIHR Clinical Research Network Portfolio Database; and the World Health Organization International Clinical Trials Registry Platform. We studied reference lists and published systematic review articles.

SELECTION CRITERIA

Test accuracy studies of any design that evaluated visual inspection in adults with lesions suspicious for melanoma, compared with a reference standard of either histological confirmation or clinical follow-up. We excluded studies reporting data for 'clinical diagnosis' where dermoscopy may or may not have been used.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted all data using a standardised data extraction and quality assessment form (based on QUADAS-2). We contacted authors of included studies where information related to the target condition or diagnostic threshold were missing. We estimated summary sensitivities and specificities per algorithm and threshold using the bivariate hierarchical model. We investigated the impact of: in-person test interpretation; use of a purposely developed algorithm to assist diagnosis; and observer expertise.

MAIN RESULTS

We included 49 publications reporting on a total of 51 study cohorts with 34,351 lesions (including 2499 cases), providing 134 datasets for visual inspection. Across almost all study quality domains, the majority of study reports provided insufficient information to allow us to judge the risk of bias, while in three of four domains that we assessed we scored concerns regarding applicability of study findings as 'high'. Selective participant recruitment, lack of detail regarding the threshold for deciding on a positive test result, and lack of detail on observer expertise were particularly problematic.Attempts to analyse studies by degree of prior testing were hampered by a lack of relevant information and by the restricted inclusion of lesions selected for biopsy or excision. Accuracy was generally much higher for in-person diagnosis compared to image-based evaluations (relative diagnostic odds ratio of 8.54, 95% CI 2.89 to 25.3, P < 0.001). Meta-analysis of in-person evaluations that could be clearly placed on the clinical pathway showed a general trade-off between sensitivity and specificity, with the highest sensitivity (92.4%, 95% CI 26.2% to 99.8%) and lowest specificity (79.7%, 95% CI 73.7% to 84.7%) observed in participants with limited prior testing (n = 3 datasets). Summary sensitivities were lower for those referred for specialist assessment but with much higher specificities (e.g. sensitivity 76.7%, 95% CI 61.7% to 87.1%) and specificity 95.7%, 95% CI 89.7% to 98.3%) for lesions selected for excision, n = 8 datasets). These differences may be related to differences in the spectrum of included lesions, differences in the definition of a positive test result, or to variations in observer expertise. We did not find clear evidence that accuracy is improved by the use of any algorithm to assist diagnosis in all settings. Attempts to examine the effect of observer expertise in melanoma diagnosis were hindered due to poor reporting.

AUTHORS' CONCLUSIONS

Visual inspection is a fundamental component of the assessment of a suspicious skin lesion; however, the evidence suggests that melanomas will be missed if visual inspection is used on its own. The evidence to support its accuracy in the range of settings in which it is used is flawed and very poorly reported. Although published algorithms do not appear to improve accuracy, there is insufficient evidence to suggest that the 'no algorithm' approach should be preferred in all settings. Despite the volume of research evaluating visual inspection, further prospective evaluation of the potential added value of using established algorithms according to the prior testing or diagnostic difficulty of lesions may be warranted.

Visual inspection and dermoscopy, alone or in combination, for diagnosing keratinocyte skin cancers in adults

BACKGROUND

Early accurate detection of all skin cancer types is important to guide appropriate management, to reduce morbidity and to improve survival. Basal cell carcinoma (BCC) is almost always a localised skin cancer with potential to infiltrate and damage surrounding tissue, whereas a minority of cutaneous squamous cell carcinomas (cSCCs) and invasive melanomas are higher-risk skin cancers with the potential to metastasise and cause death. Dermoscopy has become an important tool to assist specialist clinicians in the diagnosis of melanoma, and is increasingly used in primary-care settings. Dermoscopy is a precision-built handheld illuminated magnifier that allows more detailed examination of the skin down to the level of the superficial dermis. Establishing the value of dermoscopy over and above visual inspection for the diagnosis of BCC or cSCC in primary- and secondary-care settings is critical to understanding its potential contribution to appropriate skin cancer triage, including referral of higher-risk cancers to secondary care, the identification of low-risk skin cancers that might be treated in primary care and to provide reassurance to those with benign skin lesions who can be safely discharged.

OBJECTIVES

To determine the diagnostic accuracy of visual inspection and dermoscopy, alone or in combination, for the detection of (a) BCC and (b) cSCC, in adults. We separated studies according to whether the diagnosis was recorded face-to-face (in person) or based on remote (image-based) assessment.

SEARCH METHODS

We undertook a comprehensive search of the following databases from inception up to August 2016: Cochrane Central Register of Controlled Trials; MEDLINE; Embase; CINAHL; CPCI; Zetoc; Science Citation Index; US National Institutes of Health Ongoing Trials Register; NIHR Clinical Research Network Portfolio Database; and the World Health Organization International Clinical Trials Registry Platform. We studied reference lists and published systematic review articles.

SELECTION CRITERIA

Studies of any design that evaluated visual inspection or dermoscopy or both in adults with lesions suspicious for skin cancer, compared with a reference standard of either histological confirmation or clinical follow-up.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted all data using a standardised data extraction and quality assessment form (based on QUADAS-2). We contacted authors of included studies where information related to the target condition or diagnostic thresholds were missing. We estimated accuracy using hierarchical summary ROC methods. We undertook analysis of studies allowing direct comparison between tests. To facilitate interpretation of results, we computed values of sensitivity at the point on the SROC curve with 80% fixed specificity and values of specificity with 80% fixed sensitivity. We investigated the impact of in-person test interpretation; use of a purposely-developed algorithm to assist diagnosis; and observer expertise.

MAIN RESULTS

We included 24 publications reporting on 24 study cohorts, providing 27 visual inspection datasets (8805 lesions; 2579 malignancies) and 33 dermoscopy datasets (6855 lesions; 1444 malignancies). The risk of bias was mainly low for the index test (for dermoscopy evaluations) and reference standard domains, particularly for in-person evaluations, and high or unclear for participant selection, application of the index test for visual inspection and for participant flow and timing. We scored concerns about the applicability of study findings as of 'high' or 'unclear' concern for almost all studies across all domains assessed. Selective participant recruitment, lack of reproducibility of diagnostic thresholds and lack of detail on observer expertise were particularly problematic.The detection of BCC was reported in 28 datasets; 15 on an in-person basis and 13 image-based. Analysis of studies by prior testing of participants and according to observer expertise was not possible due to lack of data. Studies were primarily conducted in participants referred for specialist assessment of lesions with available histological classification. We found no clear differences in accuracy between dermoscopy studies undertaken in person and those which evaluated images. The lack of effect observed may be due to other sources of heterogeneity, including variations in the types of skin lesion studied, in dermatoscopes used, or in the use of algorithms and varying thresholds for deciding on a positive test result.Meta-analysis found in-person evaluations of dermoscopy (7 evaluations; 4683 lesions and 363 BCCs) to be more accurate than visual inspection alone for the detection of BCC (8 evaluations; 7017 lesions and 1586 BCCs), with a relative diagnostic odds ratio (RDOR) of 8.2 (95% confidence interval (CI) 3.5 to 19.3; P < 0.001). This corresponds to predicted differences in sensitivity of 14% (93% versus 79%) at a fixed specificity of 80% and predicted differences in specificity of 22% (99% versus 77%) at a fixed sensitivity of 80%. We observed very similar results for the image-based evaluations.When applied to a hypothetical population of 1000 lesions, of which 170 are BCC (based on median BCC prevalence across studies), an increased sensitivity of 14% from dermoscopy would lead to 24 fewer BCCs missed, assuming 166 false positive results from both tests. A 22% increase in specificity from dermoscopy with sensitivity fixed at 80% would result in 183 fewer unnecessary excisions, assuming 34 BCCs missed for both tests. There was not enough evidence to assess the use of algorithms or structured checklists for either visual inspection or dermoscopy.Insufficient data were available to draw conclusions on the accuracy of either test for the detection of cSCCs.

AUTHORS' CONCLUSIONS

Dermoscopy may be a valuable tool for the diagnosis of BCC as an adjunct to visual inspection of a suspicious skin lesion following a thorough history-taking including assessment of risk factors for keratinocyte cancer. The evidence primarily comes from secondary-care (referred) populations and populations with pigmented lesions or mixed lesion types. There is no clear evidence supporting the use of currently-available formal algorithms to assist dermoscopy diagnosis.

How accurate is the clinical and radiological evaluation of orbital lesions in comparison to surgical orbital biopsy?

AIMS

The purpose of the present study is to determine the overall and disease-related accuracy of clinical and radiological diagnosis when compared to the histology result of the surgical orbital biopsy.

METHODS

A retrospective case notes analysis of patients who underwent surgical orbital biopsy during a 12-year period involving more than 100 orbital lesions. The accuracy of clinical and radiological diagnosis was compared with histological diagnosis.

RESULTS

A total of 112 orbital biopsies were carried out in 104 eyes of 101 patients between 2003 and 2015. Correct diagnosis was reached in <50% of cases by both ophthalmologists and radiologists alike. Vascular lesions exhibit characteristic clinical and imaging features that allow for accurate diagnosis and can often be managed conservatively. The greatest challenge, both clinically and on imaging was in differentiating between inflammatory and haematological orbital lesions which represented half of our cases. There was no operative mortality and there were no post-operative complications recorded.

CONCLUSION

Surgical orbital biopsy is a safe and accurate diagnostic tool for orbital lesions of unknown aetiology and, in our opinion, remains the gold standard.

Diagnosis of aggressive subtypes of eyelid basal cell carcinoma by 2-mm punch biopsy: prospective and comparative study

OBJECTIVE

: to compare the accuracy of preoperative 2-mm punch biopsy at one site and at two sites in the diagnosis of aggressive subtypes of eyelid basal cell carcinoma (BCC).

METHODS

: we randomly assigned patients to Group 1 (biopsy at one site) and Group 2 (biopsy at two sites). We compared the biopsy results to the gold standard (pathology of the surgical specimen). We calculated the sensitivity, specificity, positive predictive value, negative predictive value, accuracy and Kappa coefficient to determine the level of agreement in both groups.

RESULTS

: we analyzed 105 lesions (Group 1: n = 44; Group 2: n = 61). The agreement was 54.5% in Group 1 and 73.8% in Group 2 (p = 0.041). There was no significant difference between the groups regarding the distribution of quantitative and qualitative variables (gender, age, disease duration, tumor larger diameter, area and commitment of margins). Biopsy at two sites was two times more likely to agree with the gold standard than the biopsy of a single site.

CONCLUSIONS

: the accuracy and the performance indicators were better for 2-mm punch biopsy in two sites than in one site for the diagnosis of aggressive subtypes of eyelid BCC.

OBJETIVO

comparar a acurácia da biópsia pré-operatória por trépano de 2mm em um sítio e em dois sítios no diagnóstico dos subtipos agressivos de carcinoma basocelular (CBC) palpebral.

MÉTODOS

os pacientes foram distribuídos aleatoriamente em Grupo 1 (biópsia em um sítio) e Grupo 2 (biópsia em dois sítios). Os resultados das biópsias foram comparados com o padrão-ouro (exame anatomopatológico da peça cirúrgica). A sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo, precisão e coeficiente Kappa foram calculados para determinar o nível de concordância nos dois grupos.

RESULTADOS

foram analisadas 105 lesões (Grupo 1: n = 44; Grupo 2: n = 61). A concordância foi de 54,5% no Grupo 1 e 73,8% no Grupo 2 (p-valor = 0,041). Não houve diferença significativa entre os grupos quanto à distribuição das variáveis quantitativas e qualitativas (sexo, idade, duração da doença, maior diâmetro do tumor, área e comprometimento de margens). A biópsia em dois sítios mostrou duas vezes mais chance de concordar com o padrão-ouro do que a biópsia de um sítio.

CONCLUSÕES

a acurácia e os indicadores de desempenho foram melhores para a biópsia por trépano de 2 mm em dois sítios do que em um sítio para o diagnóstico dos subtipos agressivos de CBC palpebral.

Accuracy and confidence in the clinical diagnosis of basal cell cancer using dermoscopy and reflex confocal microscopy

BACKGROUND

Diagnosis of suspected basal cell carcinoma (BCC) is typically confirmed with incisional biopsy before referral to final surgery.

OBJECTIVE

To investigate the clinical confidence and accuracy of physicians making a diagnosis of BCC based on dermoscopic and reflectance confocal microscopy (RCM) features.

METHODS

This study was designed as a simulation to determine the certainty and willingness to refer to surgery without previous biopsy confirmation of BCC. Study subjects were identified with suspected BCC. Dermoscopic and RCM lesion images were obtained before biopsy. Eight clinicians with various expertise levels blindly interpreted these images and chose among four hypothetical treatment options: definite BCC, refer directly to surgery without biopsy; other malignancy, perform biopsy for diagnosis; uncertain diagnosis, perform biopsy; benign, do not biopsy. Decisions for treatment were based on dermoscopic images alone and, subsequently, on dermoscopic and RCM images combined.

RESULTS

The sensitivity for referral to surgery without biopsy was 67.6% with the use of dermoscopy; the positive predictive value (PPV) was 97.0%. Adding RCM increased the sensitivity to 76.5% and the PPV to 98.6%.

CONCLUSIONS

Dermoscopy provides a high PPV for BCC. The addition of RCM to dermoscopy increases diagnostic sensitivity, particularly in less experienced dermoscopists. Physician behavior might be different if actual referrals were made for surgery without biopsy.

Weight of Decision-Making Impairs Clinical Assessment of Melanocytic Lesions

Background and Objective:

We studied the weight of decision-making on clinical assessment of melanocytic lesions judging benign, atypical, and malignant lesions; common mistakes; and total removal rates, comparing dermatologists with nondermatologists.

Methods:

Of 11,246 histopathology specimens, 3,768 had a clinical assessment of melanocytic lesions. Histopathologic diagnosis served as the gold standard.

Results:

Benign nevi were assessed most accurately (77%). Dermatologists assessed benign nevi better (p < .0001). The accuracy of clinical assessment in atypical nevi and melanoma was lower (23% and 42%, respectively). Seborrheic keratosis was the most common mistaken diagnosis. Complete removal of clinically benign nevi, atypical nevi, and melanoma was 84%, 90%, and 89%. Decision-making impaired clinical assessement of melanocytic lesions by 5% for dermatologists and 9% for nondermatologists.

Conclusion:

The accuracy of clinical assessment of melanocytic lesions is high for benign nevi, with dermatologists outperforming nondermatologists. Clinicians overestimated malignant potential. Complete removal was more frequent in suspicious lesions. Clinical decision-making impaired assessment by 5 to 9%.

Effect of preoperative evaluation by a dermatologist on diagnostic accuracy

BACKGROUND

The accuracy of the diagnosis of skin lesions has an important effect in outcomes in treatment selection and prioritization of the treatment.

OBJECTIVE

To assess the effect of preoperative evaluations by dermatologists on the diagnostic accuracy of plastic surgeons.

MATERIALS AND METHODS

A retrospective analysis was performed on 1,146 biopsies that were excised by plastic surgeons in our secondary State Hospital. The histopathologic diagnoses were divided into 2 groups according to the preoperative dermatological evaluation, with Group 1 being the lesions that were evaluated by a dermatologist before excision and Group 2 being the lesions that were not evaluated by a dermatologist before excision. The sensitivity and positive predictive values (PPVs) were calculated and compared between the 2 groups using Fisher exact test.

RESULTS

The PPVs of the malignant lesions of Groups 1 and 2 were 53.8% and 25.0%, respectively (p = .001). When Group 1 was contrasted with Group 2, the PPVs for the premalignant lesions were 71.4% and 46.8%, respectively (p = .015). The PPV for the benign lesions was 86.3% in Group 1 and 72.6% in Group 2 (p < .001).

CONCLUSION

This study demonstrated that the diagnostic accuracy of plastic surgeons was affected positively by preoperative evaluations by a dermatologist.

Clinical triage of cutaneous squamous cell carcinoma and basal cell carcinoma to avoid treatment delay: value of an electronic booking system

BACKGROUND

Provisional clinical diagnosis is the first step in planning skin surgery. Different clinical priorities are given to basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and malignant melanoma (MM). Discriminating between SCC and BCC can be difficult. The rate of misdiagnosis of SCC as BCC is reported as 5.7-87.6%, and can cause treatment delay. We have developed a web-based surgery booking system that requires clinical commitment to a putative differential diagnosis category, rather than a single diagnosis, at the time of consultation. This includes a crucial overlap category of 'SCC or SCC/BCC'.

AIM

To assess whether our system helped avoid treatment delay to patients with SCC, and to measure the number needed to treat (NNT).

METHODS

This was a retrospective analysis from April 2012 to August 2013, comprising all patients undergoing booked excisional surgery in our unit. The clinical triaging category was compared with the histological diagnosis. Sensitivity, specificity, positive predictive value, negative predictive value (NPV), NNT and mean Breslow thickness were calculated.

RESULTS

In total, 1455 lesions were excised, identifying 789 (54.2%) invasive malignancies (86 MM, 115 SCC, 583 BCC, 5 other), 100 in situ lesions and 150 dysplastic lesions. The majority (83.2%) of malignancies were designated into the correct malignant category. Misdiagnosis of SCC as BCC was 5.2%. Sensitivity and NPV for SCC were 94.8% and 99.4%, respectively. NNT was 1.26, 4.12 and 3.19 for BCC, SCC and MM respectively, and 1.73 for all malignancies. Mean invasive Breslow thickness was 1.29 mm [0.78 mm including melanoma in situ (MMIS)], and the MM to MMIS was 1.6.

CONCLUSION

An overlap triage category of 'SCC or SCC/BCC' helps to prevent delay in the treatment for patients with SCC.

Sensitivity, predictive values, pretest-posttest probabilities, and likelihood ratios of presurgery clinical diagnosis of nonmelanoma skin cancers

BACKGROUND

The precision of clinical diagnosis of skin tumors is not commonly measured and, therefore, very little is known about the diagnostic ability of clinicians.

OBJECTIVE

This study aimed to compare clinical and histopathologic diagnoses of nonmelanoma skin cancers with regard to sensitivity, predictive values, pretest-posttest probabilities, and likelihood ratios.

METHODS

Two hundred nineteen patients with 241 nonmelanoma skin cancers were enrolled in this study. Of these patients, 49.4% were female and 50.6% were male. The mean age ± standard deviation (SD) was 63.66 ± 16.44 years for the female patients and 64.77 ± 14.88 years for the male patients. The mean duration of the lesions was 20.90 ± 32.95 months. One hundred forty-eight (61.5%) of the lesions were diagnosed as basal cell carcinoma (BCC) and 93 (38.5%) were diagnosed as squamous cell carcinoma (SCC) histopathologically.

RESULTS

Sensitivity, positive predictive value, and posttest probability were calculated as 75.96%, 87.77%, and 87.78% for BCC and 70.37%, 37.25%, and 37.20% for SCC, respectively. The correlation between clinical and histopathologic diagnoses was found to be higher in BCC.

CONCLUSION

Knowledge of sensitivity, predictive values, likelihood ratios, and posttest probabilities may have implications for the management of skin cancers. To prevent unnecessary surgeries and achieve high diagnostic accuracies, multidisciplinary approaches are recommended.

Diagnosis of nonmelanoma skin cancer/keratinocyte carcinoma: a review of diagnostic accuracy of nonmelanoma skin cancer diagnostic tests and technologies

BACKGROUND

Nonmelanoma skin cancer (NMSC) is the most prevalent cancer in the light-skinned population. Noninvasive treatment is increasingly used for NMSC patients with superficial lesions, making the development of noninvasive diagnostic technologies highly relevant.

OBJECTIVE

The scope of this review is to present data on the current state-of-the-art diagnostic methods for keratinocyte carcinoma: basal cell carcinoma, squamous cell carcinoma, and actinic keratosis.

METHODS AND MATERIALS

MEDLINE, BIOSIS, and EMBASE searches on NMSC and physical and clinical examination, biopsy, molecular marker, ultrasonography, Doppler, optical coherence tomography, dermoscopy, spectroscopy, fluorescence imaging, confocal microscopy, positron emission tomography, computed tomography, magnetic resonance imaging, terahertz imaging, electrical impedance and sensitivity, specificity, and diagnostic accuracy.

RESULTS

State-of-the-art diagnostic research has been limited in this field, but encouraging results from the reviewed diagnostic trials have suggested a high diagnostic accuracy for many of the technologies. Most of the studies, however, were pilot or small studies and the results would need to be validated in larger trials.

CONCLUSIONS

Some of these new imaging technologies have the capability of providing new, three-dimensional in vivo, in situ understanding of NMSC development over time. Some of the new technologies described here have the potential to make it from the bench to the clinic.

Early melanoma diagnosis: a success story that leaves room for improvement

PURPOSE OF REVIEW

Early diagnosis has the greatest potential for short-term impact on melanoma mortality. We highlight recent trends in early melanoma detection and address the related challenges and opportunities.

RECENT FINDINGS

Significant strides have been made in the early diagnosis of melanoma. Success has been achieved through improved awareness of early signs of melanoma and identification of high-risk cohorts. Detection pressure, however, may also be resulting in the diagnosis of indolent disease, leading to unnecessary morbidity and cost. A looming imbalance of supply and demand for melanoma detection services is anticipated with the aging of the baby boom generation. Prioritization of other preventive services and a growing emphasis on cosmetic dermatology are anticipated to exacerbate this imbalance. While a paucity of hard data have precluded adoption of formal screening recommendations for melanoma, general consensus supports opportunistic screening and identification of high-risk individuals who may benefit from specialized surveillance with dermoscopy and whole-body photography. Research is needed to distinguish biologically indolent and aggressive melanoma, to develop and test evolving technologies to aid diagnosis, and to assess the utility of specific public health strategies for melanoma detection.

SUMMARY

Significant strides have been made in early melanoma detection, but multiple challenges remain.

Management of basal cell carcinoma by surveyed dermatologists in Scotland

BACKGROUND

The British Association of Dermatologists (BAD) has produced guidelines for management of basal cell carcinoma (BCC) in the UK.

OBJECTIVES

Our primary objectives were to assess the management of BCCs in Scotland and to compare it with BAD guidelines. Our secondary objectives were to audit waiting times and referral patterns.

METHODS

In phase I of the audit, dermatologists in 14 centres across Scotland prospectively registered demographic and clinical data of all lesions suspected to be BCCs over a 6-week period between October and December 2000. In phase II, details of management of these lesions were evaluated by case note review.

RESULTS

Of the 48 consultant dermatologists contacted, 42 took part in the survey. There were 524 clinically suspected BCCs seen in 470 patients; 164 lesions in 146 patients showed pathology other than BCC and were excluded from analysis, thus leaving 360 lesions available for analysis. There was wide variation in waiting times among Scottish dermatology centres. BCCs were equally distributed between the sexes, and lesions most commonly presented in those aged 71-80 years. A diagnostic biopsy was taken in 22% of lesions, and the rest were treated definitively after a clinical diagnosis of BCC, of which 90% were confirmed on histology. Nodulocystic lesions were the most common type of tumour, comprising 48% of lesions, and most BCCs were located on the head and neck region. Correlation of the histological type of BCC and treatment received showed that nodulocystic and morpheic BCCs were managed as recommended. There were more superficial BCCs treated with surgical excision than expected (22 of 34 lesions). Four of 21 recurrent tumours and 9 of 81 tumours on high-risk areas of the face were managed with curettage and cautery or cryotherapy, rather than surgical excision. Of the 297 excised tumours, 25 (9%) were incompletely excised. All the high-risk tumours and incompletely excised tumours were offered follow-up in the dermatology clinics.

CONCLUSIONS

In general, BCCs are managed according to BAD guidelines in Scotland, but waiting times vary considerably.

Electrical impedance scanning for melanoma diagnosis: a validation study

BACKGROUND

A multicenter study was conducted to test the ability of electrical impedance scanning to differentiate between benign and malignant skin lesions. The performance of a dual electrical impedance scanning/image analysis device was also assessed.

METHODS

Electrical impedance scanning measurements of 449 preoperative lesions found on 382 patients and including 53 melanomas from the trunk and extremities were performed. Results were correlated with histopathologic findings. In addition, ABCD parameters for the lesions were automatically calculated by the system.

RESULTS

Electrical impedance scanning detected melanomas of the trunk and extremities with 91 percent sensitivity and 64 percent specificity. Moreover, sensitivity of electrical impedance scanning was increased to 100 percent for in situ and thin melanomas of smaller size (n = 27). Visual examination identified as malignant only 67 percent of these early tumors (p = 0.002). Clinical examination detected 96 percent of the larger or thicker melanomas (n = 26), whereas electrical impedance scanning detected only 81 percent of them. Combined electrical impedance scanning and image analysis detected 100 percent of the melanomas, independent of their thickness, and with no significant decrease of specificity. Because of electrical differences between the head/neck and the rest of the body, the assessed electrical impedance scanning parameters were not adequate for the diagnosis of melanomas from the head and neck.

CONCLUSIONS

A validation study proved the value of electrical impedance scanning as a noninvasive technique for detection of melanoma lesions of the trunk and extremities, specifically, of in situ and thin type. In addition, image analysis was shown to be a valuable, complementary procedure. New parameters should be designed to optimize the performance of electrical impedance scanning for melanomas of the head and neck.

CLINICAL DIAGNOSIS OF SKIN TUMOURS: HOW GOOD ARE WE?

BACKGROUND

Few studies have addressed the accuracy of clinical diagnosis of skin malignancies. The present prospective study aims to determine the accuracy with which these lesions are diagnosed and attempts to identify the factors influencing the accuracy of clinical diagnosis.

METHODS

All patients undergoing surgical excision of a skin cancer with curative intent from January 2001 to December 2002 at Peter MacCallum Cancer Institute, Melbourne, Australia were prospectively studied. Data were entered into the Filemaker Pro program and analysed using the SPSS software package.

RESULTS

A total of 2582 lesions were surgically excised from 1223 patients. Of these 47% were basal cell carcinomas (BCC), 20% were squamous cell carcinomas (SCC), 0.9% were malignant melanomas (MM), and 32.1% were benign or premalignant. Tumours, benign and malignant, were found to be more common in men. The sensitivity for clinical diagnosis of malignancy was 97.5% while the positive predictive value (PPV) for clinical diagnosis of malignancy was 70.3%. BCC and SCC was diagnosed with a sensitivity of 89% and 56.3%, and PPV of 64.5% and 40.3%, respectively (P < 0.001). 23 MM were excised with a sensitivity of clinical diagnosis of 47.8% and PPV of 30.6%. Sensitivity and PPV were also assessed according to clinical experience of the surgeon, site of the lesion and whether surgery was performed for a primary or a recurrent lesion. Sensitivity and PPV were higher for lesions diagnosed by consultant surgeons when compared with surgical trainees (P < 0.001) - MM was diagnosed with a sensitivity of 100% by consultant surgeons.

CONCLUSION

The present study shows sensitivity and PPV rates comparable to published figures.