Line-field optical coherence tomography: In vivo diagnosis of basal cell carcinoma subtypes compared to histopathology.
Basal cell carcinoma (BCC) is the most common skin cancer in the general population. Treatments vary from Mohs surgery to topical therapy, depending on the subtype. Dermoscopy, reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) have gained a foothold in daily clinical practice to optimize diagnosis and subtype-oriented treatment. The new device Line-field confocal OCT (LC-OCT) allows imaging at high resolution and depth but its use is not yet been investigated in larger studies.To evaluate the main LC-OCT criteria for the diagnosis and subtyping of BCC in comparison to histopathology, OCT and RCM.Fifty-two histopathologically confirmed BCCs were evaluated for imaging criteria. Their frequency, predictive values and ROC curves were calculated. A multinominal regression with stepwise variables selection to distinguish BCC subtypes was performed.Nodular BCCs were mainly characterized by atypical keratinocytes, altered DEJ, tumour nests in the dermis, dark clefting, prominent vascularisation and white hyperreflective stroma. Superficial BCCs showed a thickening of the epidermis due to a series of tumour lobules with clear connection to the DEJ (string of pearls pattern). Infiltrative BCCs were characterized by elongated hyporeflective tumour strands, surrounded by bright collagen (shoal of fish). The overall BCC subtype agreement between LC-OCT and conventional histology was 90.4 % (95% CI: 79.0, 96.8).LC-OCT allows the non-invasive, real time identification of BCCs and their subtypes in vertical, horizontal and 3D mode compared to histology, RCM and OCT. Further larger studies are needed to better explore the clinical applications of this promising device.
Authors: C Ruini, S Schuh, C Gust, B Kendziora, L Frommherz, L E French, D Hartmann, J Welzel, E Sattler