Line‐field confocal optical coherence tomography for the in vivo real‐time diagnosis of different stages of keratinocyte skin cancer: a preliminary study

Abstract

Background The treatment of keratinocyte cancers (KC) strictly depends on their differentiation and invasiveness. Non‐invasive diagnostic techniques can support the diagnosis in real time, avoiding unnecessary biopsies. This study aimed to preliminarily define main imaging criteria and histological correlations of actinic keratosis (AK), Bowen’s disease (BD) and squamous cell carcinoma (SCC) using the novel device line‐field confocal optical coherence tomography (LC‐OCT). Methods Dermoscopy and LC‐OCT images of 73 histopathologically confirmed lesions (46 AKs, 11 BD and 16 SCCs) were included in the study. Exemplary lesions (10 AKs, 5 BD and 5 SCCs) were additionally investigated with optical coherence tomography and reflectance confocal microscopy. Results Most common LC‐OCT findings of KC in the descriptive statistics were hyperkeratosis/parakeratosis, disruption of stratum corneum, broadened epidermis, basal and suprabasal keratinocyte atypia, dilated vessels/neoangiogenesis and elastosis/collagen alterations. In the univariate multinomial logistic regression, a preserved DEJ was less common in SCC compared with AK and BD, BD displayed marked keratinocyte atypia involving all epidermal layers (bowenoid pattern), while SCC showed ulceration, increased epidermal thickness, keratin plugs, acantholysis, not visible/interrupted DEJ and epidermal bright particles. LC‐OCT increased the diagnostic confidence by 24.7% compared with dermoscopy alone. Conclusions Our study describes for the first time specific LC‐OCT features of different stages of KC and their histopathological correlates, focusing on keratinocyte morphology and architecture of the epidermis and DEJ. LC‐OCT may open new scenarios in the bedside diagnosis, treatment planning and follow‐up of KC.

Repeated exposure to fractional CO2 laser delays squamous cell carcinoma formation and prevents clinical and subclinical photodamage visualized by line‐field confocal optical coherence tomography and histology

“…In UVR‐exposed mice, photodamage was clearly identified in the epidermis through a high keratinocyte dysplasia score and in the dermis as substantially reduced structure of dermo‐fibers. These findings are consistent with the clinically observed UVR‐induced development of SCC and skin laxity 25,26 . In contrast, AFL reduced keratinocyte dysplasia and reintroduced some dermo‐fiber structure, consistent with delayed SCC formation and increased skin tightness, respectively.…”

Line-Field Confocal Optical Coherence Tomography: A New Tool for the Differentiation between Nevi and Melanomas?

“…The disadvantage of LC-OCT is the lower penetration depth compared to OCT, so it is possible that deeper tumor parts may be missed [19,20]. Due to the presentation of single cells, differential diagnoses such as sebaceous hyperplasia, actinic keratoses, and squamous cell carcinomas could be differentiated, and the proliferation degree of actinic keratoses showed a 75% concordance between LC-OCT and histology [21][22][23][24]. This high single cell resolution is the reason why we assumed that even melanocytic lesions can be evaluated with LC-OCT.…”

Comparison of reflectance confocal microscopy and line‐field optical coherence tomography for the identification of keratinocyte skin tumours

“…Comprehensive descriptions of AK/SCC under LC-OCT and RCM have already been performed. 5,15,16 As awaited, tumour strands were seen in SCC and not in AKs. When the analysis was conducted on the ten invasive SCC, LC-OCT and not RCM could detect tumor strands, probably because only three invasive SCCs were visible beneath the DEJ in RCM.…”

“…Comprehensive descriptions of AK/SCC under LC‐OCT and RCM have already been performed 5,15,16 . To our better knowledge, this is the first study that compares single criteria of RCM and LC‐OCT in AK and SCC.…”