Impact of in vivo reflectance confocal microscopy on the number needed to treat melanoma in doubtful lesions

Atypical Clinical Presentation of Xeroderma Pigmentosum in a Patient Harboring a Novel Missense Mutation in the XPC Gene: The Importance of Clinical Suspicion

BACKGROUND

Xeroderma pigmentosum (XP) is a genodermatosis caused by abnormal DNA repair. XP complementation group C (XPC) is the most frequent type in Mediterranean countries. We describe a case with a novel mutation in the XPC gene.

CASE

A healthy Caucasian male patient was diagnosed with multiple primary melanomas. Digital follow-up and molecular studies were carried out.

RESULTS

During digital follow-up 8 more additional melanomas were diagnosed. Molecular studies did not identify mutations in CDKN2A, CDK4 or MITF genes. Two heterozygous mutations in the XPC gene were detected: c.2287delC (p.Leu763Cysfs*4) frameshift and c.2212A>G (p.Thr738Ala) missense mutations.

CONCLUSION

The p.Thr738Ala missense mutation has not been previously described. Missense mutations in the XPC gene may allow partial functionality that could explain this unusual late onset XP. Atypical clinical presentation of XPC could be misdiagnosed when genetic aberrations allow partial DNA repair capacity.

In vivo reflectance confocal microscopy of equivocal melanocytic lesions detected by digital dermoscopy follow-up

BACKGROUND

Digital follow-up is a useful method for the detection of melanoma in atypical mole syndrome patients. The combination of digital follow-up (DFU) and reflectance confocal microscopy (RCM) could be useful to increase the accuracy in the classification of equivocal lesions in atypical mole syndrome patients.

OBJECTIVES

To assess the impact of RCM analysis on sensitivity and specificity of digital follow-up in a high-risk melanoma setting.

METHODS

Retrospective study with dermoscopy and RCM of consecutive equivocal atypical melanocytic lesions exhibiting changes in digital dermoscopy in a referral centre.

RESULTS

Sixty-four lesions from 51 patients were included. Thirteen changing lesions (20.3%) corresponded to eight melanomas in situ and five invasive melanomas with Breslow less than 1 mm. Fifty-one lesions corresponded to melanocytic naevus with variable atypia. Total dermoscopy scores were not different between naevus and melanoma neither in the baseline (mean 5.06 and 5.24; P = 0.37) nor in the follow-up dermoscopic control (mean 5.44 and 5.55; P = 0.37). The only significant dermoscopic feature associated with melanoma in multivariate analysis was the presence of streaks after follow-up (P = 0.027; OR = 3.6; CI 1.50-8.70). The confocal microscopy evaluation (by means both the Modena and Barcelona methods) showed a sensitivity and specificity for the diagnosis of melanoma of 100% and 69% respectively. Based on our experience, the combination of RCM and DFU could have avoided 35 of 51 nevi excised.

CONCLUSIONS

Reflectance confocal microscopy evaluation of equivocal lesions detected by DFU improved the accuracy in the detection of melanoma. The combination of dermoscopy, DFU and confocal microscopy in equivocal lesions can be useful to dramatically reduce the number of excisions of benign lesions in atypical mole syndrome patients.

CD271 is expressed in melanomas with more aggressive behaviour, with correlation of characteristic morphology by in vivo reflectance confocal microscopy

BACKGROUND

Melanoma is the most highly aggressive type of skin cancer. Its resistance to existing treatments and the rapid rise in incidence underscore the importance of acquiring a better understanding of melanomagenesis.

OBJECTIVES

To assess the impact of reflectance confocal microscopy (RCM) on the description of cell morphology, which may influence the growth pattern and changes with increasing tumour severity, correlating with biological aspects.

METHODS

A retrospective analysis of 30 primary melanomas in vivo, evaluated by RCM, to correlate cell morphology and cellular arrangement with a marker of melanoma progression (CD271) using immunohistochemical evaluations.

RESULTS

Typical cells organized in dermal nests with peculiar in vivo confocal morphology result in melanoma with high malignancy and positivity to CD271. This architecture might be due to the presence of a type of cells, intrinsically predisposed to invasion, as a result of dedifferentiation programming, revealed by expression of the neural crest marker CD271.

CONCLUSIONS

With the hypothesis that dedifferentiated cells would be strongly responsible for initiation of tumour development and progression, we propose that CD271 detection could be associated with RCM evaluation in order to detect more aggressive melanoma subtypes.

Integration of reflectance confocal microscopy in sequential dermoscopy follow-up improves melanoma detection accuracy

BACKGROUND

Successful treatment of melanoma depends on early diagnosis, but its varied clinical presentation means that no single noninvasive method or criterion can provide reliable detection in all cases.

OBJECTIVES

To determine whether combining sequential dermoscopy imaging with reflectance confocal microscopy (RCM) can improve melanoma detection and reduce the burden of unnecessary excisions.

METHODS

We conducted a retrospective study with median follow-up of 25 months. We included equivocal pigmented lesions that lacked clear dermoscopy criteria for melanoma at baseline but were excised subsequently because of changes during digital monitoring. RCM imaging was performed before excision. Main melanoma dermoscopy features, seven-point checklist score at baseline, and changes in structure and/or colour, and development of new melanoma-specific criteria at follow-up (scored as major, moderate or minor) were considered. Main melanoma RCM criteria were evaluated and diagnosis was made. Histopathological diagnosis was the reference standard for defining parameter frequency and diagnostic accuracy.

RESULTS

Seventy lesions were included. Major changes were more frequently correlated with melanoma diagnosis, although one-third (four of 12) of melanomas showed moderate or minor changes. Cytological atypia and architectural disarrangement on RCM were correlated with melanoma diagnosis. A correct melanoma diagnosis was achieved with RCM in almost all cases (11 of 12, 92%). Referring for excision only those lesions with RCM-positive features and/or presenting major changes at digital dermoscopy follow-up, theoretically 27 of 58 naevi could be saved from surgery.

CONCLUSIONS

Integration of RCM in the clinical and instrumental strategy for managing difficult pigmented lesions provided additional diagnostic information useful in the decision-making process.

Reflectance confocal microscopy as a second-level examination in skin oncology improves diagnostic accuracy and saves unnecessary excisions: a longitudinal prospective study

BACKGROUND

Dermatoscopy increases both the sensitivity and specificity of melanoma diagnosis. Reflectance confocal microscopy (RCM) is a noninvasive technique that complements dermatoscopy in the evaluation of equivocal lesions at cellular resolution.

OBJECTIVES

To determine prospectively the potential impact of confocal microscopy when implemented in a routine melanoma diagnosis workflow.

METHODS

Patients referred to a single melanoma clinic were consecutively enrolled. At dermatoscopy, patients were referred to one of the following pathways: (i) no further examination or (ii) RCM examination. On examination atypical lesion(s) were referred for either (a) RCM documentation (lesions with consistent suspicious clinical/dermatoscopic criteria, already qualified and scheduled for surgical excision) or (b) RCM consultation for equivocal lesions, where RCM diagnosis would determine lesion definite outcome (excision or digital follow-up).

RESULTS

Reflectance confocal microscopy examination was performed for 41% of 1005 patients enrolled. In two-thirds of these cases RCM influenced the lesion outcome. The systematic application of RCM for equivocal lesions saved over 50% of benign lesions from unnecessary excision. The number needed to excise a melanoma was 6·8 with RCM examination, compared with a hypothetical 14·6 without RCM evaluation.

CONCLUSIONS

Reflectance confocal microscopy as a second-level examination to dermatoscopy proved to be highly accurate in diagnosis and reduced the number of unnecessary excisions. Improved accuracy, considering that RCM enabled the detection of the six melanomas (2%) in the group of 308 lesions eligible for follow-up, also minimizes the risk of referring a melanoma to digital dermatoscopy monitoring, and potentially losing the patient to follow-up.

Dermoscopic difficult lesions: an objective evaluation of reflectance confocal microscopy impact for accurate diagnosis

BACKGROUND

Early detection of melanoma is the main objective to ensure a high survival rate. In some cases melanoma diagnosis still remain difficult and this leads to unnecessary excisions.

OBJECTIVE

The aim of this study was to detect the most relevant Reflectance confocal microscopy (RCM) features for the detection of dermoscopic difficult melanomas.

METHOD

A total of 322 lesions were selected from database and were evaluated on dermoscopy according to the 7-point checklist score, in blind from histological diagnosis. We classified the lesions into three categories: (i) 'featureless' lesions with score ranging between 0 and 2; (ii) 'positive-borderline' moles with score between 3 and 4 and (iii) 'positive-clear cut' lesions with score from 5 to 10. We evaluated confocal features of the 'featureless' lesions and of the 'positive-borderline' lesions. Evaluated confocal features were as follows: presence of pagetoid cells, cell shape (roundish or dendritic) and number (< 5 or >5 cells per mm(2) ), overall architecture (ringed, meshwork, clods and non-specific pattern); architectural disorder, presence of cytological atypia (>5 cells per mm(2) ) and cells arranged in nests.

RESULTS

Among 322 lesions 70 were melanomas and 252 were nevi. According to the classification based on the 7-point checklist score, 130 'featureless lesions' (score 0-2) including six melanomas, and 102 'positive-borderline' moles (score 3-4) including 17 melanomas, were identified. Round pagetoid cells >5 cells per mm(2) and/or architectural disorder on RCM were found in all of six melanomas with featureless dermoscopy. Round pagetoid infiltration and five or more atypical cells at the DEJ were found in 16 positive 'borderline melanomas'.

CONCLUSIONS

RCM represents a rapid non-invasive technique that can aid early diagnosis of dermoscopic difficult melanomas. Use of RCM on lesions with clinical and/or dermoscopic suspect of malignancy may reduce the number of unnecessary excision increasing the rate of accurate diagnoses.

Automated delineation of dermal-epidermal junction in reflectance confocal microscopy image stacks of human skin

Reflectance confocal microscopy (RCM) images skin noninvasively, with optical sectioning and nuclear-level resolution comparable with that of pathology. On the basis of the assessment of the dermal-epidermal junction (DEJ) and morphologic features in its vicinity, skin cancer can be diagnosed in vivo with high sensitivity and specificity. However, the current visual, qualitative approach for reading images leads to subjective variability in diagnosis. We hypothesize that machine learning-based algorithms may enable a more quantitative, objective approach. Testing and validation were performed with two algorithms that can automatically delineate the DEJ in RCM stacks of normal human skin. The test set was composed of 15 fair- and 15 dark-skin stacks (30 subjects) with expert labelings. In dark skin, in which the contrast is high owing to melanin, the algorithm produced an average error of 7.9±6.4 μm. In fair skin, the algorithm delineated the DEJ as a transition zone, with average error of 8.3±5.8 μm for the epidermis-to-transition zone boundary and 7.6±5.6 μm for the transition zone-to-dermis. Our results suggest that automated algorithms may quantitatively guide the delineation of the DEJ, to assist in objective reading of RCM images. Further development of such algorithms may guide assessment of abnormal morphological features at the DEJ.

Surveillance for treatment failure of lentigo maligna with dermoscopy and in vivo confocal microscopy: new descriptors

BACKGROUND

Nonsurgical treatment (radiotherapy, imiquimod) is increasingly employed for the management of lentigo maligna (LM). While the diagnosis of LM remains difficult, the detection of treatment failure is even more challenging.

OBJECTIVES

To describe the sensitivity and specificity for the diagnosis of LM of individual features and methods using dermoscopy and in vivo reflectance confocal microscopy (RCM) to aid in the detection of treatment failure of LM following nonsurgical treatment.

METHODS

A retrospective study of dermoscopy and RCM images (blinded to the correlation with pathology) in patients with biopsy-confirmed LM who were undergoing nonsurgical treatment in two referral institutions - one in Sydney, Australia, and the other in Barcelona, Spain. Ninety-eight patients were treated nonsurgically for LM during the period 2006-2012. Thirty-one patients had abnormal dermoscopy or RCM evaluation, and had a biopsy that identified LM recurrence in 15 patients and nonmelanoma diagnoses in 16 patients (one Bowen disease, 15 solar changes).

RESULTS

The diagnosis of treatment failure was difficult with dermoscopy, with a sensitivity of 80% and specificity of 56%, even with the interpretation of an expert. The best criterion was asymmetric hyperpigmented follicular openings, but this was present in only 47% of treatment failure LM. Isolated, very fine brown dots ('dust' appearance) correlated highly with the diagnosis of treatment failure LM (73% sensitivity and 88% specificity) and with pagetoid cells seen with RCM. The LM score, comprising six criteria, had a specificity of 94% and sensitivity of 100%.

CONCLUSIONS

These methods and descriptors should help to manage the diagnosis of treatment failure.