Surveillance of patients at high risk for cutaneous malignant melanoma using digital dermoscopy

BACKGROUND: Dermoscopy has improved the sensitivity and specificity of clinical diagnosis of melanoma from 60% to over 90%. However, in order not to miss melanoma a certain percentage of suspicious but benign lesions has to be excised. OBJECTIVES: To evaluate the dermoscopic changes and the rates of excision in benign melanocytic naevi and cutaneous malignant melanoma in long-term follow-up of high-risk patients using digital dermoscopy. METHODS: Digital dermoscopic images of 2015 atypical melanocytic naevi in 196 high-risk patients were analysed retrospectively. Among others, the following data were collected for each naevus: changes in surface area, overall architecture, dermoscopic patterns and distribution of pigmentation. All tumours suspicious for melanoma or showing asymmetrical changes were excised. RESULTS: During a median follow-up time of 25 months 128 (6.4%) of all naevi showed changes in size or architecture. Eighty-six per cent of all changes in patients who attended more than one visit were observed at the first follow-up visit. Thirty-three lesions showing changes were excised and two melanomas in situ and 31 melanocytic naevi were diagnosed. CONCLUSIONS: Follow-up examinations using digital dermoscopy revealed unchanged morphology in the large majority of melanocytic naevi. Excisions were only performed in cases of asymmetrical growth, asymmetrical changes of pigmentation, or development of dermoscopic features indicative of melanoma. The ratio of 33 lesions excised in order to identify two melanomas in situ seems reasonable and may be further reduced in future.     

Dermoscopic diagnosis by a trained clinician vs. a clinician with minimal dermoscopy training vs. computer-aided diagnosis of 341 pigmented skin lesions: a comparative study

BACKGROUND: In the last few years digital dermoscopy has been introduced as an additional tool to improve the clinical diagnosis of pigmented skin lesions. OBJECTIVE: To evaluate the validity of digital dermoscopy by comparing the diagnoses of a dermatologist experienced in dermoscopy (5 years of experience) with those of a clinician with minimal training in this field, and then comparing these results with those obtained using computer-aided diagnoses. METHODS: Three hundred and forty-one pigmented melanocytic and non-melanocytic skin lesions were included. All lesions were surgically excised and histopathologically examined. Digital dermoscopic images of all lesions were framed and analysed using software based on a trained artificial neural network. Cohen's kappa statistic was calculated to assess the validity with regard to the correct diagnoses of melanoma and non-melanoma. RESULTS: Sensitivity was high for the experienced dermatologist and the computer (92%) and lower for the inexperienced clinician (69%). Specificity of the diagnosis by the experienced dermatologist was higher (99%) than that of the inexperienced clinician (94%) and the computer assessment (74%). Notably, computer analysis gave a higher number of false positives (26%) compared with the experienced dermatologist (0.6%) and the inexperienced clinician (5.5%). CONCLUSIONS: Our results indicate that analysis either by a trained dermatologist or an artificial neural network-trained computer can improve the diagnostic accuracy of melanoma compared with that of an inexperienced clinician and that the computer diagnosis might represent a useful tool for the screening of melanoma, particularly at centres not experienced in dermoscopy.     

Objective follow-up of atypical melanocytic skin lesions: a retrospective study

Various authors have suggested that information from longitudinal observation (follow-up) of dynamic changes in atypical melanocytic pigmented skin lesions (MPSL) could enable identification of early malignant melanoma escaping initial observation due to an absence of specific clinical and dermoscopic features. The aim of our retrospective study was to determine the existence of numerical variables regarding changes in MPSL that could be useful to differentiate early melanomas and atypical nevi. The study was carried out in two Italian dermatology Centres. Digital dermoscopy analyzers (DB-Mips System) were used to evaluate dermoscopic images of 94 equivocal pigmented skin lesions under observation for 6–12 months and then excised because of changes across time (29 melanomas and 65 nevi). The analyzer evaluates 49 parameters grouped into four categories: geometries, colours, textures and islands of colour. The ROC curve designed on the 49 digital dermoscopy analysis parameters showed good accuracy. At sensitivity (SE) = specificity (SP), it correctly classified 89.3% of cases. When objective pigmented skin lesion parameters were considered together with their objective changes over 6–12 months, a decisive increase in discrimination capacity was obtained. At SE = SP accuracy was 96.3%. Analysis of the parameters of our model and statistical analysis enabled us to interpret/identify the most significant factors of modification and differentiation of lesions, providing quantitative insights into the diagnosis of equivocal MPSL and demonstrating the utility of objective/numerical follow-up.     

Availability of digital dermoscopy in daily practice dramatically reduces the number of excised melanocytic lesions: results from an observational study

Background Digital dermoscopy has been shown to permit an earlier detection of melanoma. However, few studies have investigated its added value in reducing unnecessary excisions in everyday clinical practice. Objectives To compare, in daily practice, the efficiency of three dermoscopy methods: dermoscopy alone with little training, dermoscopy alone with adequate training and dermoscopy with adequate training and access to digital dermoscopy, and to confirm the safety of this latter approach. Methods Thirty‐six dermatologists working without digital dermoscopy were divided into two groups according to their training in dermoscopy. The third group constituted of two dermatologists working in a pigmented lesion clinic with access to the digital dermoscopy technique and eight additional dermato‐logists working in the same dermatology department. These 46 dermatologists included all presumed melanocytic lesions excised over a period of 1 year. The primary endpoint was the melanoma/nonmelanoma ratio (M/NM‐R); secondary endpoints were the ratio of ‘problem’ naevi to common naevi (PN/CN‐R), specificity and sensitivity for the diagnosis of melanoma, in situ/invasive melanoma ratio, and the mean Breslow thickness. Results In total, 1865 excised lesions, including 231 melanomas, were included. In the digital dermoscopy availability group (DD‐G) the M/NM‐R was significantly better (1/2·43), as was the PN/CN‐R (1/1·48) (P < 0·001 in both cases). The specificity was significantly higher in the DD‐G and significantly higher for trained examiners as compared with examiners with little training. More that one‐third of all melanomas discovered by digital dermoscopy were in situ, and the mean Breslow thickness was 0·32 mm for the invasive ones. Conclusions The reduction of unnecessary excisions when using digital dermoscopy compared with dermoscopy alone in our study suggests that access to digital dermoscopy offers a better management of pigmented lesions in daily practice. The high number of early lesions diagnosed by this technique confirms that its use is safe.     

Impact of dermoscopy on the management of high-risk patients from melanoma families: a prospective study

Few studies have investigated the impact of dermoscopy on the management of relatives from melanoma families. The objective of this study was to assess the impact of dermoscopy on clinical diagnosis and management decisions in high-risk familial melanoma patients. In a prospective study 132 consecutive patients were recruited from the pigmented lesions clinic of a tertiary reference centre for familial melanoma. Dermatologists expert in dermoscopy identified 49 suspicious pigmented lesions and recorded pre- and post-dermoscopy diagnoses and management decisions. Dermoscopy was performed in 37% of the patients. Two melanomas were identified. Dermoscopy did not influence sensitivity (1.0), but resulted in 42% fewer excisions, increasing specificity from 0.53 to 0.74 (p = 0.031). Dermoscopy resulted in a large reduction in the number of unnecessary excisions. These results suggest that the main effect of dermoscopy in clinical practice for this high risk population is a significant increase in specificity, rather than sensitivity.     

The significance of multiple blue-grey dots (granularity) for the dermoscopic diagnosis of melanoma

BACKGROUND: The presence of multiple blue-grey dots (MBGD) is widely used by clinicians to decide if a pigmented lesion should be removed, but only little is known about their significance. OBJECTIVES: To evaluate the significance of MBGD for the dermoscopic diagnosis of melanoma. METHODS: In part 1 we retrospectively evaluated 340 pigmented lesions for the presence and morphological appearance of granularity. One hundred and seventy melanomas were included and matched with 170 benign and dysplastic naevi which were randomly chosen from our collection. In part 2, 3773 lesions were examined prospectively in at-risk patients: all lesions with granularity were recorded, surgically removed and subjected to histopathological examination. RESULTS: In part 1, granularity was found in 26.5% of the benign lesions and 93.5% of melanomas. The presence of granularity, granularity at the periphery, irregularly distributed granularity and granularity in association with red and white colour were statistically highly significant for the diagnosis of melanoma (P < 0.001). In part 2, granularity was found in 1.08% of the 3773 lesions and more frequently in sun-damaged skin. Sensitivity for the diagnosis of melanoma was 85% and specificity 99%. CONCLUSIONS: After the revision of many lesions with MBGD, we concluded that the term 'granularity' better describes this entity. Lesions with irregular granularity (periphery, irregularly distributed) should be removed especially if they are associated with red, blue or white colour. Lesions with a benign dermoscopy pattern which have granularity with a regular appearance and involving only a small portion of the lesion do not require surgical excision.     

Addition of dermoscopy to conventional naked-eye examination in melanoma screening: a randomized study

OBJECTIVE: We sought to assess the difference in lesion management between combined examination (naked-eye and dermoscopy) and conventional naked-eye examination in evaluations for melanoma; and to assess the impact on patient treatment of facilities for digital follow-up of diagnostically equivocal lesions. METHODS: We conducted a randomized, controlled trial at a pigmented lesion clinic in a university hospital. A total of 938 consecutive subjects presenting between November 1, 2001, and March 31, 2002, were eligible and 25 were excluded because they were younger than 12 years of age; hence 913 subjects were enrolled. Participants were randomized to combined examination with mandatory excision of equivocal lesion (arm B) and with possibility of digital follow-up according to the clinician's decision (arm C), or to conventional naked-eye examination (mandatory excision of equivocal lesion) (arm A). The same pigmented lesion clinic staff examined all subjects. RESULTS: Combined examination determined a significant reduction in the percentage of patients referred for operation (9.0% vs 15.6%) (P =.013). When facilities for digital follow-up of equivocal lesions were available, the percentage of patients classified as harboring lesions difficult to diagnose increased (group C, 35.8%; group B, 17.8%; P <.01). About half of them were immediately referred for operation whereas the remainder submitted to second examination (digital follow-up). Two melanomas (1 in situ and 1 invasive, 0.40-mm thick) were diagnosed after second examination performed 6 months later. The number of melanomas eventually excised within the study were similar among the 3 allocation groups (3, 2, and 3, respectively). CONCLUSIONS: the addition of dermoscopy to conventional naked-eye examination is associated with a significant reduction of number of pigmented skin lesions excised for diagnostic verification. The possibility of digital follow-up of equivocal lesions is associated with a not negligible occurrence of initial melanomas left unexcised until the second consultation.     

Seguimiento digitalizado combinado en población con alto riesgo de desarrollar un melanoma maligno: análisis retrospectivo de 152 pacientes

BackgroundDigital dermoscopy (DD) has been found to improve the accuracy of melanoma diagnosis in high-risk patients. A 2-step approach combining DD and total-body photography (TBP) can facilitate the detection of new lesions or early macroscopic changes in existing lesions.ObjectivesThe aim of this study was to determine the number of biopsies needed to diagnose melanoma and to describe the clinical and dermoscopic characteristics of melanoma diagnosed in patients with pigmented lesions under follow-up with DD and TBP.Patients and methodsRetrospective study of 152 patients with a high risk of melanoma who were followed using a 2-step digital approach at Hospital del Mar in Barcelona, Spain, between 2002 and 2016. We analyzed the characteristics of pigmented lesions excised after macroscopic changes were detected by periodic DD and TBD.ResultsBiopsy results of 99 lesions (84 dysplastic nevi, 13 melanomas, and 2 compound melanocytic nevi) showed a ratio of benign melanocytic lesions to melanomas of 1:6.6. The mean Breslow thickness was 0.19 mm. Macroscopic changes were significantly more common in melanomas than in melanocytic nevi (P = 0.018). Dermoscopic findings associated with melanoma were asymmetric growth and focal structural changes (P < 0.001). The specific features associated with a diagnosis of melanoma were asymmetry (P < 0.001), a reverse pigment network (P = 0.011), atypical globules (P = 0.011), and polymorphous vessels (P = 0.045).ConclusionsTBP follow-up is a useful tool for the early diagnosis of melanoma. In our series, 50% of melanomas diagnosed during digital follow-up were detected by observation of a new lesion via TBP mapping or macroscopic changes in an existing lesion. Dermoscopic follow-up is essential in patients at high risk for melanoma as both melanocytic nevi and melanoma show a range of specific dermoscopic features, and a diagnosis of melanoma can only be based on a record of changes in the appearance of lesions during follow-up.     

Impact of dermoscopy and short‐term sequential digital dermoscopy imaging for the management of pigmented lesions in primary care: a sequential intervention trial

Background Studies have shown the benign to malignant ratio of excised pigmented skin lesions is suboptimal in primary care. Objectives To assess the impact of dermoscopy and short‐term sequential digital dermoscopy imaging (SDDI) on the management of suspicious pigmented skin lesions by primary care physicians. Methods A total of 63 primary care physicians were trained in the use of dermoscopy and SDDI (interventions) and then recruited pigmented lesions requiring biopsy or referral in routine care by naked eye examination. They were then given a dermatoscope and the option of a SDDI instrument, and change of diagnosis and management was assessed. Results Following the use of the interventions on 374 lesions a total of 163 lesions (43·6%) were excised or referred, representing a reduction of 56·4%. Of the 323 lesions confirmed to be benign, 118 (36·5%) were excised or referred, leading to a reduction of 63·5% (P < 0·0005) in those requiring excision or referral. The baseline naked eye examination benign to melanoma ratio was 9·5 : 1 which decreased to 3·5 : 1 after the diagnostic interventions (P < 0·0005). Of the 42 malignant lesions included in the study (34 melanoma, six pigmented basal cell carcinoma and two Bowen disease) only one in situ melanoma was incorrectly managed (patient to return if changes occur) resulting in the correct management of 97·6% and 97·1% of malignant pigmented lesions and melanoma, respectively. Conclusions In a primary care setting the combination of dermoscopy and short‐term SDDI reduces the excision or referral of benign pigmented lesions by more than half while nearly doubling the sensitivity for the diagnosis of melanoma.     

Dermoscopy as a second step in the diagnosis of doubtful pigmented skin lesions: How great is the risk of missing a melanoma?

BACKGROUND: Little is known about the occurrence of false negatives in the diagnosis of melanoma using dermoscopy in clinical practice: in the literature dermoscopy only increased the accuracy of diagnosis of equivocal lesions that were to undergo biopsy anyway. AIM AND METHODS: We collected the 81 lesions clinically diagnosed as probable melanomas by experienced specialists (from a series of 256 pigmented skin lesions submitted to excisional biopsy) and reviewed them for possible false negative results in the diagnosis of melanoma using in vivo dermoscopy and dermoscopy performed on slide images. Both procedures were carried out by the same experienced dermatologists who classified the lesions clinically. RESULTS: Dermoscopy made on slide images (observers blinded for clinical features of the lesions) yielded three false negative results (91% sensitivity) in a group of 35 histologically confirmed melanomas. In vivo dermoscopy showed better results, with no melanomas missed (100% sensitivity). The frequency of false positive results in the diagnosis of melanoma was 13.5% (11 of 81) with dermoscopy on slide images and 2.5% (two of 81) with in vivo dermoscopy. CONCLUSIONS: Only in vivo dermoscopy by fully trained dermatologists with both clinical and dermoscopic experience avoids the risk of misclassification of melanomas otherwise correctly classified on clinical grounds.     

Pre-operative diagnosis of pigmented skin lesions: in vivo dermoscopy performs better than dermoscopy on photographic images

BACKGROUND: Epiluminescence microscopy (ELM) (dermoscopy, dermatoscopy) is a technique for non-invasive diagnosis of pigmented skin lesions that improves the diagnostic performance of dermatologists. Little is known about the possible influence of associated clinical features on the reliability of dermoscopic diagnosis during in vivo examination. OBJECTIVE: To compare diagnostic performance of in vivo dermoscopy (combined clinical and dermoscopic examination) with that of dermoscopy performed on photographic slides (pure dermoscopy). DESIGN: This case series comprised 256 pigmented skin lesions consecutively identified as suspicious or equivocal during examination in a general dermatological clinic. Clinical examination and in vivo dermoscopy were performed before excision by two trained dermatologists. The same observers carried out dermoscopy on photographic slides at a later time, and these three diagnostic classifications were reviewed together with the histological findings for the individual lesions. This was carried out in a university hospital. RESULTS: In vivo dermoscopy performed better than dermoscopy on photographic slides for classification of pigmented skin lesions compared with histological diagnosis, and both performed better than general clinical diagnosis. In vivo dermoscopic diagnosis of melanoma showed 98.1% sensitivity, 95.5% specificity and 96.1% diagnostic accuracy while dermoscopic diagnosis of melanoma on photographic slides was less reliable with 81.5% sensitivity, 86.7% specificity and 85.2% diagnostic accuracy. In particular, diagnosis of melanoma based on photographic slides led to nine false negative cases (three in situ, six invasive; thickness ranges 0.2-1.5 mm). CONCLUSIONS: In vivo dermoscopy, i.e. combined clinical and dermoscopic examination, is more reliable than dermoscopy on photographic slides. In clinical practice, therefore, in vivo dermoscopy cannot be considered independent from associated clinical characteristics of the lesions, which help the trained observer to reach a more precise classification. This may have implications on the reliability of ELM diagnosis made by an observer not fully trained in the clinical diagnosis of pigmented skin lesions or by a remote observer during digital ELM teleconsultation.     

Digital dermoscopy analysis of atypical pigmented skin lesions: a stepwise logistic discriminant analysis approach

Background: Digital microscopy is a non-invasive diagnostic technique enabling determination of characteristics that cannot be appreciated by direct observation. If correctly applied, this technique can be useful for the diagnosis of pigmented skin lesions.
Purpose: To evaluate the utility of digital microscopy for analysing atypical benign and malignant pigmented skin lesions exploiting digital numerical filtering and automatic measurements.
Methods: Forty-eight parameters were identified as possible discriminating variables, and were grouped in four categories: geometries, colours, textures, and islands of colour. Statistical analysis was used to identify the variables with the highest discriminating power.
Results: The high quality of the digital image made it possible to observe diagnostic signs in pigmented skin lesion images, acquired by the present technique, in great detail. Specially designed filtering enhanced certain diagnostic patterns. Stepwise discriminant analysis selected only 10 variables (the means of these variables were higher in melanomas than in nevi).
Conclusions: The combined use of digital dermoscopy and stepwise logistic discriminant analysis made it possible to single out the best objective variables for distinguishing atypical nevi and early melanoma.     

Laypersons’ sensitivity for melanoma identification is higher with dermoscopy images than clinical photographs

Background Most melanomas are first recognized by patients themselves or by their friends and family. Objectives To assess the ability of laypersons to identify melanomas using dermoscopy images. Methods This is an image‐based study using laptop computers in the community. Seventeen laypersons were given a one‐page educational brochure on the AC Rule for melanoma (asymmetry, colour variation). These laypersons and three expert dermoscopists completed two image sets, each containing a series of 100 pigmented skin lesions. Set 1 contained five melanomas, while set 2 contained 20 melanomas. Participants viewed a clinical image followed by a dermoscopy image for each lesion. For each image a score of 0–10 was assigned for asymmetry and colour, and then an overall assessment was made for suspicion of melanoma. Mean estimates have been calculated for sensitivity and specificity. Results Laypersons achieved a clinical sensitivity of 91·2% and a significantly higher dermoscopy sensitivity of 94·0%, P = 0·013. This improvement was not associated with a significant change in overall specificity, which for the clinical image was 64·2% and with dermoscopy was 62·0%, P = 0·97. Conclusions These results indicate that laypersons may be able to use dermoscopy to identify more melanomas than naked eye examination alone. Further study into the practice of dermoscopy by laypersons is warranted.     

Short-term digital surface microscopic monitoring of atypical or changing melanocytic lesions.

OBJECTIVE: To examine the outcome of short-term digital surface microscopic monitoring of suspicious or changing atypical melanocytic lesions. DESIGN: Digital surface microscopic (oil epiluminescence microscopy, and dermoscopy) images of clinically melanocytic lesions were taken with a color calibrated 3 CCD video instrument. In general, lesions were moderately atypical, flat or only slightly raised, without a history of change or surface microscopic evidence of melanoma, or were mildly atypical lesions with a history of change. Lesions were monitored during a 2.5- to 4.5-month period (median, 3.0 months). With the exception of overall change in pigmentation consistent with that seen in surrounding skin (solar exposure changes), any morphologic change after monitoring was considered an indication to excise. SETTING: Sydney Melanoma Unit, Sydney, Australia (a referral center). PATIENTS: A consecutive sample of 318 lesions from 245 patients (aged 4-81 years). MAIN OUTCOME MEASURE: Specificity for the diagnosis of melanoma. RESULTS: Of the 318 lesions, 81% remained unchanged. Of the 61 lesions that showed morphologic changes, 7 (11% of changed and 2% of total lesions) were found to be early melanoma (5 in situ and 2 invasive with a Breslow thickness of 0.25 mm and 0.28 mm, respectively). None of these melanomas developed any classic surface microscopic features of melanoma and therefore could be identified only by morphologic change. The specificity for the diagnosis of melanoma by means of short-term digital monitoring was 83%. CONCLUSION: On the assumption that all melanoma will change during the monitored period, surface microscopy digital monitoring is a useful adjunct for the management of melanocytic lesions.     

Self-detected cutaneous melanomas in Italian patients

Self-detection of suspicious pigmented skin lesion combined with rapid referral to dermatologic centres is the key strategy in the fight against melanoma. The investigation of factors associated with pattern of detection of melanoma (self- vs. nonself-detection) may be useful to refine educational strategies for the future. We investigated the frequency of melanoma self-detection in a Mediterranean population at intermediate melanoma risk. A multicentric survey identified 816 consecutive cases of cutaneous melanoma in the period January to December 2001 in 11 Italian clinical centres belonging to the Italian Multidisciplinary Group on Melanoma. All patients filled a standardized questionnaire and were clinically examined by expert dermatologists. Self-detected melanomas were 40.6%, while the remaining lesions were detected by a dermatologist (18.5%), the family physician (15.2%), other specialists (5%), the spouse (12.5%), a friend or someone else (8.2%). Variables associated with self-detected melanomas were female sex, young age, absence of atypical nevi, knowledge of the ABCD rule, habit of performing skin self-examination. Self-detected melanomas did not differ from nonself-detected tumours in term of lesion thickness; however, patients with self-detected melanomas waited a longer period before having a diagnostic confirmation (patient's delay) (> 3 months: odds ratio, 3.89; 95% confidence interval, 2.74-5.53). In order to reduce the patients' delays, educational messages should adequately stress the need for a prompt referral to a physician once a suspicious pigmented lesion is self-detected.     

Reflectance confocal microscopy in the diagnosis of partially and completely amelanotic melanoma: report on seven cases

Background The clinical diagnosis of amelanotic melanoma is often challenging, because the classical clinical and dermoscopic features of pigmented melanoma are usually missing. The reflectance confocal microscopy (RCM) offers an additional possibility of an in vivo diagnosis of both pigmented and amelanotic melanoma lesions. Objectives To test the value of RCM in vivo in the preoperative prediction of melanoma lesions lacking significant pigment and to compare the results with the evaluation by dermoscopy and histopathology. Methods We examined seven patients with the clinically uncertain differential diagnosis of partially or completely amelanotic melanoma by RCM and dermoscopy prior to surgical excision of the lesions according to the previously suggested dermoscopy algorithm and RCM score for melanoma. The following RCM features were evaluated: major criteria scored +2 (non‐edged papillae, cytological atypia at the dermo‐epidermal junction) and minor criteria +1 (roundish pagetoid cells, widespread pagetoid infiltration, nucleated cells within dermal papillae, cerebriform cell clusters). The dermoscopic evaluation included the following criteria: polymorphous vessels, dotted and linear irregular vessels, hairpin vessels, pink‐erythematous colour, milky red areas, irregularly shaped depigmentation, blue‐grey dots and subtle pigmentation. Results The preoperative in vivo RCM analysis revealed common features of melanoma also found in pigmented melanoma lesions. All lesions showed a score above three in the applied RCM algorithm which was proposed earlier as the threshold for malignancy. In dermoscopy, five of seven lesions showed characteristic vascular changes. Conclusion In vivo RCM is a valuable tool in the preoperative diagnosis of partially and completely amelanotic tumours suspicious for melanoma in addition to dermoscopic evaluation.     

Improvement of malignant/benign ratio in excised melanocytic lesions in the 'dermoscopy era': a retrospective study 1997-2001

BACKGROUND: Because of the many limitations of studies based on the diagnostic setting of excised lesions, the impact of dermoscopy (epiluminescence microscopy, dermatoscopy) in melanoma screening during practice remains to be established. OBJECTIVES: We assumed that effects of the use of dermoscopy on some indicators of diagnostic performance in melanoma screening should be traceable retrospectively; therefore, we analysed the impact of routine dermoscopy use on the malignant/benign ratio in excised melanocytic lesions. METHODS: Preoperative and histological diagnosis of 3053 melanocytic lesions [319 melanomas (10.4%)] consecutively diagnosed and excised at the Department of Dermatology, University of Florence in the period 1997-2001 inclusive were retrieved. Six dermatologists who selected the lesions to excise and who performed preoperative diagnosis were divided into two groups according to their use of dermoscopy in routine activity (n = 2 dermoscopy users and n = 4 nonusers). The study period was divided into a predermoscopy period (1997), a shift phase (1998) and a dermoscopy period (1999-2001). RESULTS: During the study period, the malignant/benign ratio improved in dermoscopy users only (from 1 : 18 to 1 : 4.3, P = 0.037). No significant difference was found for nonusers (from 1 : 11.8 to 1 : 14.4). Dermoscopy users were more likely to have a melanoma diagnosed within a series of excised lesions than nonusers, even taking into account potential confounders such as sex, age and study period by means of multivariate analysis (odds ratio 1.55, 95% confidence interval 1.17-2.01). The percentage of 'problem' naevi (naevi with architectural disorder with or without cytological atypia and Spitz or Reed naevi) over the total number of excised lesions was higher in dermoscopy users than in nonusers (year 2001, 51.6% vs. 40.9%, P = 0.014). Similar findings were obtained after exclusion from the data set of lesions excised for cosmetic reasons. CONCLUSIONS: The adoption of dermoscopy in routine melanoma screening is followed by an improvement of the malignant/benign ratio in excised lesions, suggesting a more appropriate selection of pigmented lesions referred to surgery. Because of the possible limitations of a retrospective study design, future confirmation of this finding by means of a prospective, randomized study is advisable. The introduction of dermoscopy in routine practice may have major implications in large-scale melanoma screening with cost savings and a reduction of the dermosurgery workload.     

Dysplastic naevus vs. in situ melanoma: digital dermoscopy analysis

BACKGROUND: To date, much confusion exists about the biological significance of dysplastic naevi and about the relationship between melanocytic dysplasia and clinical atypia. OBJECTIVES: To use a digital dermoscopy analyser with a series of 'borderline' pigmented skin lesions (i.e. dysplastic naevi and in situ melanomas) to find correlation between the studied variables and to determine their discriminating power with respect to histological diagnosis. METHODS: The pigmented skin lesions (n = 174) were histologically examined by three experienced dermatopathologists and identified as in situ melanomas (n = 38) and dysplastic naevi (n = 136). The system evaluated 48 parameters as possible discriminant variables, grouped into four categories: geometry, colours, textures and islands of colour. Once the lesions were analysed (stepwise discriminant analysis), sensitivity, specificity and accuracy were calculated. RESULTS: At the end of the stepwise procedure the percentage of cases classified correctly was 71.8%. Of 136 dysplastic naevi only 98 were classified correctly, while 27 of 38 in situ melanomas were recognized correctly. CONCLUSIONS: We conclude that there are so far no digital dermoscopic criteria that can clearly distinguish dysplastic naevi from in situ melanomas.