Criteria for melanocytic lesions in LC-OCT.

BACKGROUND: Line-field confocal optical coherence tomography (LC-OCT) is an emerging diagnostic tool with imaging depth reaching ~400 µm and a novel three-dimensional (3D) cube providing cellular resolution. As far as we are aware, there are only a limited number of papers that have reported diagnostic criteria for melanocytic lesions using this technique, and none of them have been multicentric. OBJECTIVES: Our aim was to establish the diagnostic criteria for melanocytic lesions using LC-OCT and identify the most significant architectural and cytologic features associated with malignancy. METHODS: A retrospective evaluation of 80 consecutive melanocytic lesions from a prospective multicentric data set spanning three European centres was conducted. We excluded facial, acral and mucosal lesions from the study. Dermoscopic and LC-OCT images were evaluated by a consensus of four observers. Multivariate logistic regression with backward elimination was employed. RESULTS: The main melanoma diagnostic criteria include detecting >10 pagetoid cells in 3D acquisition, irregular 3D epidermal architecture, disrupted dermoepidermal junction (DEJ) and clefting. Significant risk factors were irregular 3D epidermal architecture, >10 pagetoid cells, dendritic cells at DEJ without underlying inflammation. Novel malignancy criteria in vertical view were DEJ disruption and clefting around atypical melanocyte nests. Exclusive melanoma features were epidermal nests, epidermal consumption, dense dermal nests with atypia. Protective features in the absence of any malignancy indicators were DEJ ring pattern, cobblestone, elongated rete ridges (vertical), well-defined DEJ and wave pattern (vertical). CONCLUSIONS: A series of diagnostic criteria for the identification of melanocytic lesions with LC-OCT have been established. Validation of these criteria in clinical practice through future studies is essential to further establish their utility.

Understanding the anatomy of dermoscopy of melanocytic skin tumours: Correlation in vivo with line-field optical coherence tomography.

BACKGROUND: Early melanoma detection is the main factor affecting prognosis and survival. For that reason, non-invasive technologies have been developed to provide a more accurate diagnosis. Recently, line-field confocal optical coherence tomography (LC-OCT) was developed to provide an in vivo, imaging device, with deep penetration and cellular resolution in three dimensions. Combining the advantages of conventional OCT and reflectance confocal microscopy, this tool seems to be particularly suitable for melanocytic lesions. OBJECTIVES: The objective of this study was to identify and describe the correlation between specific dermoscopic criteria and LC-OCT features in three dimensions associated with melanocytic lesions. METHODS: Dermoscopic and LC-OCT images of 126 melanocytic lesions were acquired in three different centres. The following dermoscopic criteria have been considered: reticular pattern, dots and globules, structureless areas, blue-whitish veil, regression structures, negative network, homogeneous pattern, streaks and blotches. RESULTS: 69 (55%) benign and 57 (45%) malignant lesions were analysed. A regular reticular pattern was found associated in the 75% of the cases with the presence of elongated rete ridges with pigmented cells along the basal layer, while atypical reticular pattern showed an irregular organization of rete ridges with melanocytic hyperplasia, broadened and fused ridges and elongated nests. Both typical and atypical dots and globules were found associated with melanocytic nests in the dermis or at the dermoepidermal junction (DEJ), as well as with keratin cysts/pseudocysts. Grey globules corresponded to the presence of melanin-containing dermal inflammatory cells (melanophages) within the papillae. Structureless brown/black areas correlated with alterations of the DEJ. We observed the same DEJ alterations, but with the presence of dermal melanophages, in 36% of the cases of blue/white/grey structureless areas. A description of each LC-OCT/dermoscopy correlation was made. CONCLUSIONS: LC-OCT permitted for the first time to perform an in vivo, 3D correlation between dermoscopic criteria and pathological-like features of melanocytic lesions.

Line-field confocal optical coherence tomography of basosquamous carcinoma: a case series with histopathological correlation.

BACKGROUND: Basosquamous carcinoma (BSC) is a rare and potentially aggressive cutaneous neoplasm combining histopathological features of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Line-field confocal optical coherence tomography (LC-OCT) is a new, non-invasive imaging technique featuring excellent resolution and penetration. To date, studies about the use of LC-OCT in the BCC and SCC fields are available, but similar investigations are lacking in the BSC field. OBJECTIVE: The goal of the present study was to identify/describe LC-OCT criteria of BSC. METHODS: Consecutively enrolled BSCs were imaged with dermoscopy and LC-OCT prior to surgical excision. Dermoscopic and LC-OCT images were evaluated, and histopathological slides were reviewed. RESULTS: Six BSCs from six patients [four (66.7%) males and two (33.3%) females; mean age 76.5 (62-96) years] were included. Identified LC-OCT criteria for BSC included BCC-associated (dermal lobules with millefeuille pattern, dilated vessels, bright cells within the epidermis, bright cells within lobules, stromal stretching, stromal brightness) and SCC-associated features (acanthosis, hyperkeratosis, disarranged epidermal architecture, broad strands, elastosis and glomerular vessels). Interruption of the dermal-epidermal junction and ulceration represented overlapping criteria. CONCLUSION: Line-field confocal-OCT is a new promising technique that may support the non-invasive recognition of BSC through the simultaneous detection of BCC-associated and SCC-associated features. We hypothesize that the use of LC-OCT might be helpful not only in the diagnostic setting but also in the follow-up surveillance for an early identification of recurrences. Further larger studies are needed to prove this hypothesis.

Line-field confocal optical coherence tomography for actinic keratosis and squamous cell carcinoma: a descriptive study.

BACKGROUND: Early and accurate diagnosis of cutaneous squamous cell carcinomas (SCCs) and actinic keratoses (AK) is fundamental to reduce their associated morbidity and to select the correct treatment. Line-field confocal optical coherence tomography (LC-OCT) is a new imaging device that can characterize healthy skin and basal cell carcinoma, but no large studies on keratinocyte cell tumours have yet been published. AIM: To identify and describe LC-OCT criteria associated with SCC and AK, and to compare LC-OCT findings in these tumours. METHODS: A retrospective observational multicentre study was conducted. Lesions were imaged with the LC-OCT device before surgery and examined histologically. LC-OCT criteria for AK/SCC were identified and their presence was evaluated in all study lesions. Univariate and multivariate analyses were performed to compare AK and SCCs, and to investigate differences between in situ and invasive tumours. RESULTS: In total, 158 patients with 50 AK and 108 SCCs (62 in situ and 46 invasive) were included. Cytological and architectural alterations were found in most lesions, and differences were found between AK and SCCs. Although the visualization of the dermoepidermal junction (DEJ) was often hampered by hyperkeratosis and acanthosis, an outlined DEJ without broad strands was observed in almost all AK and almost all in situ SCCs, but in only three invasive SCCs (P < 0.001) when the DEJ was detectable. CONCLUSION: Our results suggest that LC-OCT can help clinicians in the identification of AK and SCC and their differentiation, providing a real-time and noninvasive examination. Further studies are needed to confirm our data.

Flat scalp melanoma dermoscopic and reflectance confocal microscopy features correspond to histopathologic type and lesion location.

BACKGROUND: Dermoscopy and Reflectance Confocal Microscopy (RCM) features of scalp melanoma according to lesion location and histopathology have not been fully investigated. OBJECTIVES: To reveal dermoscopic and RCM features of scalp melanoma according to lesion location and histopathology. METHODS: We retrospectively retrieved images of suspicious, atypical excised, flat melanocytic lesions of the scalp, assessed on dermoscopy and RCM at five centres, from June 2007 to April 2020. Lesions were classified according to histopathological diagnoses of nevi, lentigo maligna melanoma (LM/LMM) or superficial spreading melanoma (SSM). Clinical, dermoscopic and RCM images were evaluated; LM/LMM and SSM subtypes were compared through multivariate analysis. RESULTS: Two hundred forty-seven lesions were included. In situ melanomas were mostly LM (81.3%), while invasive melanomas were mostly SSM (75.8%). Male sex, baldness and chronic sun-damaged skin were associated with all types of melanomas and in particular with LM/LMM. LMs were mostly located in the vertex area and SSM in the frontal (OR: 8.8; P < 0.05, CI 95%) and temporal (OR: 16.7; P < 0.005, CI 95%) areas. The dermoscopy presence of pseudo-network, pigmented rhomboidal structures, obliterated hair follicles and annular-granular pattern were associated with LM diagnoses, whereas bluish-white veil was more typical of SSM. Observations on RCM of atypical roundish and dendritic cells in the epidermis were associated with SSM (42.4%) and dendritic cells with LM (62.5%) diagnoses. Folliculotropism on RCM was confirmed as a typical sign of LM. CONCLUSIONS: Flat scalp melanomas reveal specific dermoscopic and RCM features according to histopathologic type and scalp location.

Super-high magnification dermoscopy can aid the differential diagnosis between melanoma and atypical naevi.

BACKGROUND: Dermoscopy is the most widely used noninvasive imaging technique for the clinical diagnosis of melanoma (MM). Super-high (× 400) magnification dermoscopy (D400) has recently been developed; compared with traditional dermoscopy, it can reveal additional features, down to the identification of single melanocytes in the skin. OBJECTIVES: To evaluate which structures are visible at D400 and to compare them in atypical naevi and MMs. METHODS: A prospective observational multicentre study was conducted. We enrolled patients who were identified as having atypical melanocytic skin lesions by clinical and/or × 20 magnification dermoscopy (D20) examination, and who were assigned to either excision or follow-up. Lesions were imaged by videodermoscopy at D20 and D400. The presence of pigmented cells and their features were assessed at D400. RESULTS: In total, there were 79 patients with 57 naevi and 31 MMs. Of the total 88 lesions, 63 (71.6%) were given a histological diagnosis, while the others were followed up for ≥ 12 months, during which they showed no change and were all diagnosed as naevi. Pigmented cells were identified in > 90% of the lesions at D400. Compared with naevi, MMs had a higher frequency of scattered, large, irregular (in shape and size), dendritic/roundish, violet/blue pigmented cells under D400 (P < 0.001). Moreover, dots (P < 0.01), out-of-focus blue structureless areas (P < 0.01) and vessels (P < 0.001) were also more frequent in MMs than in naevi at D400. CONCLUSIONS: This study showed that D400 can reveal many elements not otherwise visible in traditional D20 dermoscopy, such as pigmented cells and their morphology, which could be useful for the diagnosis of MM.

Line-field confocal optical coherence tomography of basal cell carcinoma: a descriptive study.

BACKGROUND: Early diagnosis and subtype classification of basal cell carcinoma (BCC) are crucial to reduce morbidity and optimize treatment. Good accuracy in differentiating BCC from clinical imitators has been achieved with existing diagnostic strategies but lower performance in discriminating BCC subtypes. Line-field confocal optical coherence tomography (LC-OCT) is a new technology able to combine the technical advantages of reflectance confocal microscopy and OCT. OBJECTIVES: To identify and describe LC-OCT criteria associated with BCC and explore their association with BCC subtypes. METHODS: Basal cell carcinoma were imaged with a handheld LC-OCT device before surgical excision. LC-OCT images were retrospectively evaluated by three observers for presence/absence of criteria for BCC. Multivariate logistic regression models were used to find independent predictors of BCC subtypes. RESULTS: Eighty-nine histopathologically proven BCCs were included, of which 66 (74.2%) were pure subtypes [superficial BCC (sBCC): 19/66 (28.8%); nodular BCC (nBCC): 31/66 (47.0%); infiltrative BCC (iBCC): 16/66 (24.2%)]. Lobules, blood vessels and small bright cells within epidermis/lobules were the most frequent criteria for BCC. LC-OCT criteria independently associated with sBCC were presence of hemispheric lobules, absence of lobule separation from the epidermis, absence of stretching of the stroma; with nBCC were presence of macrolobules, absence of lobule connection to the epidermis; and with iBCC were presence of branched lobules. CONCLUSIONS: This was the first study describing the characteristics of BCC under LC-OCT examination. We proposed morphologic criteria, which could be potentially useful for diagnosis and subtype classification of BCC, as well as for its therapeutic management. Future studies are needed to assess these hypotheses.

The impact of anatomical location and sun exposure on the dermoscopic recognition of atypical nevi and early melanomas: usefulness of an integrated clinical-dermoscopic method (iDScore).

BACKGROUND: The anatomical location of atypical melanocytic skin lesion (aMSL) was never combined into an algorithm for discriminating early melanomas (EM) from atypical nevi (AN). AIMS: To investigate the impact of body location on the intuitive diagnosis performed in teledermoscopy by dermatologists of different skill levels. A further aim was to evaluate how the integration of the body location could improve an algorithm-aided diagnosis. METHODS: We retrospectively collected 980 standardized dermoscopic images of aMSL cases (663 AN, 317 EM): data on the anatomical location were collected according to 15 body sites classified into 4 macro-areas of chronically/frequently/seldom/rarely exposure. Through a teledermatology web platform, 111 variously skilled dermoscopists performed either the intuitive diagnosis and 3 algorithm-assisted diagnostic tests (i.e. iDScore, 7-point checklist, ABCD rule) on each case, for a total of 3330 examinations. RESULTS: In the rarely photoexposed area (side, bottom, abdomen), AN were the most tricky (i.e. highest quote of false positives), due to a frequent recognition of dermoscopic features usually considered as suggestive for melanoma in these lesions; the EM at these sites received the highest quote of false negatives, being generally interpreted as 'featureless' according to these traditional parameters, that were more frequently displayed on the chronically photoexposed area. In rarely and seldom photoexposed area, intuitive diagnosis fails to achieve adequate accuracy for all aMSLs, as the ABCD rule and the 7-point checklist; by applying the iDScore algorithm the diagnostic performance was increased by 15% in young and 17% in experts. CONCLUSIONS: The body location of an aMSL can affect the quality of intuitive dermoscopic diagnosis, especially in sun-protected areas. Accuracy can be improved by using the iDScore algorithm that assigns a different partial score of each body site.

Validation of an integrated dermoscopic scoring method in an European teledermoscopy web platform: the iDScore project for early detection of melanoma.

BACKGROUND: Although live and teledermoscopic examination has been successfully used to achieve non-invasive diagnosis of melanocytic skin lesions (MSLs), early melanoma (EM) and atypical nevi (AN) continue to be a challenge, and none of the various algorithms proposed have been sufficiently accurate. We designed a scoring classifier diagnostic method, the iDScore that combines clinical data of the patient with dermoscopic features of the MSL. OBJECTIVE: To test the accuracy of the iDScore in differentiating EM from AN in a teledermoscopy setting and to compare it with intuitive diagnosis, the ABCD rule and the seven-point checklist. MATERIALS AND METHODS: A dedicated teledermoscopy web platform was designed. This involved the following: (i) collecting a large integrated clinical-historical-dermoscopic data set of difficult MSLs from eight European dermatology centres; (ii) online testing, education and training in using the iDScore. A total of 904 images were combined with age, sex, lesion diameter and body site data and evaluated on the platform by 111 participants with four levels of skill in dermoscopy. Each testing session consisted of 30 blind cases to examine consecutively by the above four methods. 'Management decisions' and personal participant data were also recorded. RESULTS: iDScore-aided diagnosis achieved satisfactory diagnostic accuracy for all lesions, irrespective of centre of affiliation, showing an average AUC of 0.776 in all participant testing sessions. All skill groups improved their accuracy by 10-16% with respect to intuitive diagnosis and the other methods, showing high concordance and avoiding wrong management decisions. CONCLUSION: We demonstrated the validity of the iDScore method for managing suspicious MSLs in a large multicentric data set and a teledermoscopic setting. The platform designed for the iDScore project provides ready support for physicians of any dermoscopy skill level and is useful for education and training.

Nipple and areola lesions: review of dermoscopy and reflectance confocal microscopy features.

The differential diagnosis of nipple and areola complex (NAC) lesions encompasses a large spectrum of conditions from benign tumours to inflammatory diseases that could be challenging to recognize on clinical ground. While melanoma (MM) of the NAC is exceedingly rare, benign lesions are more frequent but could be difficult to distinguish from MM. Besides MM, other malignant tumours can affect this area and in particular Paget's disease (PD). For clinically doubtful lesions, biopsy is required, with possible functional and aesthetic consequences in this sensitive area. Dermoscopy and reflectance confocal microscopy (RCM) are widely used techniques for the diagnosis of many skin lesions, but their use for NAC lesions is not well established. The objective of this study was to evaluate current literature on these imaging techniques for NAC lesions. We searched in Medline, PubMed and Cochrane database all studies up to November 2018 dealing with dermoscopy, RCM and this special site. We found that the most described malignant tumour was PD and that only two primary MMs of the NAC have been reported with these imaging techniques. Although there are few data on diagnostic accuracy of non-invasive imaging techniques for NAC lesions, it seems that dermoscopy and RCM can add relevant information to be integrated with clinical examination for the diagnosis of NAC lesions and in particular for the differential diagnosis of PD and eczema.