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 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.

Cross-reactivity in beta-lactams after a non-immediate cutaneous adverse reaction: experience of a reference centre for toxic bullous diseases and severe cutaneous adverse reactions.

BACKGROUND: Cross-reactivity among beta-lactam antibiotics (BL) is essentially reported in immediate hypersensitivity. OBJECTIVES: To evaluate cross-reactivity beyond BLs in patients with non-immediate cutaneous adverse drug reaction (non-immediate CADR) managed in a dermatology reference centre of toxic bullous and severe CADRs. PATIENTS/MATERIALS/METHODS: We conducted a retrospective single-centre study in consecutive patients consulting between 2010 and 2018 with an active BL-suspected non-immediate CADR and explored by cutaneous tests [patch tests (PT) and intradermal tests (P-IDR)] for at least three penicillin's subclasses and amino- and non-amino-cephalosporins (at least one aminocephalosporin). Cross-reactivity among subclasses was investigated for patients with positive tests. RESULTS: We included 56 patients, among whom 46 amoxicillin-suspected were and seven cephalosporin-suspected. Twenty-nine had severe CADR, and 27 had non-immediate maculopapular exanthema (MPE). Twenty-two had positive tests (18 for AS and four for CS). Among the 18 positive amoxicillin-suspected, 10 (55.6%) showed cross-reactivity with one or more other BL: 9 (50%) with another penicillin and 3 (16.5%) with a non-aminocephalosporin. No amoxicillin- or cephalosporin-suspected patient showed cross-reactivity with aztreonam or carbapenems. P-IDR showed cross-reactivity only once. CONCLUSION: After a suspected BL-induced non-immediate CADR, a large allergologic exploration is needed to confirm the diagnosis and evaluate cross-reactivity. In our population including cases of severe CADRs and MPE with late delay of onset, cross-reactivity was frequent and PT was sufficient to this purpose. The frequent cross-reactivity among penicillins encourages stopping this whole family and to test cephalosporins, aztreonam and carbapenems for which cross-allergies are rarer.