Cutaneous squamous cell carcinoma, a type of non-melanoma skin cancer, is a form of keratinocyte carcinoma that stands as one of the most prevalent cancers, exhibiting a rising frequency. This review provides an overview of the latest literature on imaging methods for diagnosing squamous cell carcinoma (SCC) and actinic keratosis (AK). It discusses the diagnostic criteria, advantages, and disadvantages of various techniques such as dermatoscopy, skin ultrasound (US), in vivo and ex-vivo reflectance confocal microscopy (RCM), and line-field confocal optical coherence tomography (LC-OCT). These methods offer benefits including non-invasiveness, rapidity, comprehensive lesion imaging, and enhanced sensitivity, but face challenges like high costs and the need for specialized expertise. Despite obstacles, the use of these innovative techniques is expected to increase with ongoing technological advancements, improving diagnosis and treatment planning for keratinocyte carcinomas. Standardizing LC-OCT imaging algorithms for AK, Bowen’s disease, and SCC remains an area for further research.

Skin ultrasound (US) is a relatively new imaging technique, for which interest has grown significantly in the last decade. Properties such as mobility, real-time imaging and lack of irradiation or sedation, have made it a useful tool in completing the clinical examination. The use of probes of different frequencies has managed to improve the US technique, offering the possibility of obtaining high quality images. Thus, by using high-frequency and ultra-high frequency US, subclinical information can be obtained with a wide applicability in dermatological pathology. In this paper we aim to discuss the main uses of skin US in non-tumoral pathology (inflammatory and autoimmune pathology).