Reflectance Confocal Microscopy and Optical Coherence Tomography as additional non-invasive tools in Basal Cell Carcinoma diagnosis

Aims: Basal Cell Carcinoma (BCC) is the most common malignant tumor worldwide with a significantly growing incidence rate over the past years, and a variety of new, innovative diagnostic methods have been introduced to its diagnosis process in recent decades. In this research, we would like to focus on reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) with particular emphasis on their role in BCC diagnosis. Our goal is to introduce and describe these imaging techniques and evaluate their diagnostic accuracy. Methods: The literature review was conducted using the PubMed database. Publications from 2004–2025 were searched combining following phrases: „basal cell carcinoma”, „BCC”, „diagnosis”, „optical coherence tomography”, „OCT”, „reflectance confocal microscopy”, „RCM”, „diagnostic methods”, „BCC characteristics”, „BCC features”. The literature review included various types of publications such as narrative and systematic reviews, randomized controlled trials (RCTs), cohort studies, meta-analyses, and expert consensus papers. Results: RCM demonstrates excellent diagnostic performance in BCC detection, with sensitivity and specificity reaching up to 100%, and enables non-invasive visualization of critical histological features. Its imaging depth is limited to approximately 250–300 µm. OCT provides deeper imaging (up to 2 mm), with a sensitivity of 92.4% and a specificity of 86.9%, and may contribute to distinguishing BCC subtypes. Conclusions: OCT allows for deeper tissue penetration, however, RCM provides superior image resolution compared to OCT. Like RCM, the reliability of OCT interpretation depends heavily on clinician experience, and there is currently no official training curriculum. However, artificial intelligence models are being introduced to assist in image analysis and reduce inter-observer variability. Despite the growing use of non-invasive techniques in BCC diagnosis, skin biopsy with histopathological analysis remains the definitive diagnostic gold standard.