Confocal Microscopy for Diagnosis and Management of Cutaneous Malignancies: Clinical Impacts and Innovation

Abstract

Cutaneous malignancies are common malignancies worldwide, with rising incidence. Most skin cancers, including melanoma, can be cured if diagnosed correctly at an early stage. Thus, millions of biopsies are performed annually, posing a major economic burden. Non-invasive skin imaging techniques can aid in early diagnosis and save unnecessary benign biopsies. In this review article, we will discuss in vivo and ex vivo confocal microscopy (CM) techniques that are currently being utilized in dermatology clinics for skin cancer diagnosis. We will discuss their current applications and clinical impact. Additionally, we will provide a comprehensive review of the advances in the field of CM, including multi-modal approaches, the integration of fluorescent targeted dyes, and the role of artificial intelligence for improved diagnosis and management.

Keywords: clinical impacts in confocal microscopy in cutaneous oncology; confocal microscopy; ex vivo confocal microscopy; in vivo confocal microscopy; innovations and advances in confocal microscopy in cutaneous oncology; reflectance confocal microscopy.

Figure 1

(A–C) Reflectance confocal microscopy (RCM) images of (A) basal cell carcinoma (BCC) showing tumor nodules (red asterisk), (B) squamous cell carcinoma showing an atypical honeycomb pattern at the spinosum layer with prominent vessels (yellow arrow), and (C) melanoma showing clusters of atypical melanocytes (red arrows) in the epidermis and around a hair follicle (yellow asterisk). Field of view: (A–C) = 500 × 500 µm. Image A courtesy of Ms. Rozina Zeidan, Clinical Research Specialist, Memorial Sloan Kettering Cancer Center.

Figure 2

(A) An ex vivo confocal microscopy (EVCM) device with an attached computer screen for visualization of images in real-time. A fresh tissue from skin is mounted on a glass slide (white arrow) for imaging on the device and its digital hematoxylin and eosin (H&E) image (red arrow) is visible on the screen. (B) An EVCM image of a basal cell carcinoma in DHE mode showing nodular and infiltrative components (green arrows). Tumor nodules and cords appear purple due to fluorescent signals from nuclei, while stroma (green five-pointed star) appears pink due to reflectance signal, simulating H&E staining. Image A courtesy of Dr. Julia Kahn, Medical Graduate Student, Memorial Sloan Kettering Cancer Center.

Figure 3

(A,B) Optical coherence tomography (OCT) images of tumor nodules (red asterisks) with clefting (orange arrows) from the BCC shown in Figure 1A acquired with (A, at left) an RCM-OCT probe, and (B, at right) high-resolution OCT device. Field of view: (A) = 2 × 1 mm; (B) = 500 × 400 µm. Images (A,B) courtesy of Ms. Rozina Zeidan, Clinical Research Specialist, Memorial Sloan Kettering Cancer Center.