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.

Viscoelasticity assessment of tumoral skin with the use of a novel contact-free palpation methodology based upon surface waves.

The ensuing pilot investigation sheds new light on characterizing tumoral and non-tumoral human skin mechanical properties that will not only assist the dermatologist's diagnosis but also could constitute the creation of an Artificial Intelligence database for upcoming research. A modern, non-invasive, and contact-free methodology-UNDERSKIN-was developed, and hinges upon Fourier transform computations that permit the analysis of surface wave dispersion with a specific skin inversion model and viscoelastic model. It yields a detailed look at how particle movements of the medium propagate throughout its near sub-surface, hence a novel knowledge of the mechanical responses of skin tumors. The research results display the tumors' viscoelastic responses alongside their respective healthy skin outcomes for each skin layer as well as the dermatologist's touch analysis. Although dermatologists are capable of sensing and having a fair overall assessment of what they are palpating, they are unable heretofore to quantify it and inform where the firmness or softness derives from, which it is necessary to be acquainted with so as to perform an accurate diagnosis, prognosis, treatment, future surgery, and teledermatology.

Line-field confocal optical coherence tomography: a new tool for non-invasive differential diagnosis of pustular skin disorders.

BACKGROUND: The spectrum of pustular skin disorders (PSD) is large and particularly challenging, including inflammatory, infectious and amicrobial diseases. Moreover, although pustules represent the unifying clinical feature, they can be absent or not fully developed in the early stage of the disease. The line-field confocal optical coherence tomography (LC-OCT) is a recently developed imaging technique able to perform a non-invasive, in vivo, examination of the epidermis and upper dermis, reaching very high image resolution and virtual histology. OBJECTIVES: We aimed to investigate the potentialities of LC-OCT in the non-invasive differential diagnosis of a series of 11 PSD with different aetiology, microscopic features, body location and incidence rates. MATERIALS AND METHODS: Complete LC-OCT imaging (i.e. 2D/3D frames, videos) was performed on a total of 19 patients (10 females and 9 males) aged between 35 and 79 years. Images were blindly evaluated and compared with corresponding histopathologic findings. RESULTS: The LC-OCT imaging was able to detect with high accuracy the pustule structure including shape, margins, morphology and cellular content, along with peculiar epidermal and adnexal alterations in each condition, including: Acute Generalized Exanthematous Pustulosis, Generalized pustular psoriasis, Generalized pustular figurate erythema, Subcorneal Pustular Dermatosis, Intraepidermal IgA pustulosis, Palmoplantar pustulosis, Palmoplantar pustular psoriasis. Herpetic whitlow, Acrodermatitis continua of Hallopeau, Vesicopustular Sweet syndrome and Vesicopustular Eosinophilic cellulitis, with pustular appearance, were also compared. CONCLUSIONS: The new LC-OCT can represent a rapid, non-invasive and painless tool which can help differentiating among PSD of different aetiology and microscopic morphology in clinical mimickers in daily practice.

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.

FDG PET biomarkers for prediction of survival in metastatic melanoma prior to anti-PD1 immunotherapy.

Our aim was to analyse whether biomarkers extracted from baseline 18F-FDG PET before anti-PD1 treatment contribute to prognostic survival information for early risk stratification in metastatic melanoma. Fifty-six patients, without prior systemic treatment, BRAF wild type, explored using 18F-FDG PET were included retrospectively. Our primary endpoint was overall survival (OS). Total metabolic tumoral volume (MTV) and forty-one IBSI compliant parameters were extracted from PET. Parameters associated with outcome were evaluated by a cox regression model and when significant helped build a prognostic score. Median follow-up was 22.1 months and 21 patients died. Total MTV and long zone emphasis (LZE) correlated with shorter OS and served to define three risk categories for the prognostic score. For low, intermediate and high risk groups, survival rates were respectively 91.1% (IC 95 80-1), 56.1% (IC 95 37.1-85) and 19% (IC 95 0.06-60.2) and hazard ratios were respectively 0.11 (IC 95 0.025-0.46), P = 0.0028, 1.2 (IC 95 0.48-2.8), P = 0.74 and 5.9 (IC 95 2.5-14), P < 0.0001. To conclude, a prognostic score based on total MTV and LZE separated metastatic melanoma patients in 3 categories with dramatically different outcomes. Innovative therapies should be tested in the group with the lowest prognosis score for future clinical trials.

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.

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.

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.