In vivo confocal microscopy in the daily practice of the dermatologic surgeon

ABSTRACT 

New imaging methods, such as optical coherence tomography, magnetic resonance and high frequency ultrasonography, have been developed for use in dermatology.Among the new methods, in vivo reflectance confocal microscopy, has presented the fastest growth in large cutaneous oncology centers and has generated the greatest number of articles in the literature recently, due to its resolution – similar to histological resolution. In vivo confo- cal microscopy has been particularly useful given the many limitations of the dermosco- pic diagnosis of cutaneous neoplasias, especially of achromic or hypopigmented lesions, lesions in the face or in mucous membranes. Some studies have also suggested conside- rable utility in the assessment of surgical margins and in determining the best area of the body for carrying out excisional biopsies.This study briefly describes how the confocal laser reflectance microscope works and discusses some of the issues that arise in its use in the daily practice of dermatologic surgeons. 

INTRODUCTION

Significant improvements in image quality and the clinical applicability of imaging suggest a promising future for the non- invasive screening and diagnosis of skin tumors. 1 Great advan- ces have been achieved with the extensive use of dermoscopy; previously confined primarily to academic settings, dermoscopy is increasingly used in dermatologic practices and is becoming an indispensable tool in the evaluation of pigmented lesions.The use of dermoscopy is known to significantly enhance the preci- sion of clinical examinations in the early diagnosis of melano- ma, increasing the accuracy of the diagnosis by up to 20% 2,3 compared to examination with the naked eye.

Melanocytic lesions, however, remain a diagnostic challen- ge. Given the possibility of melanoma, the goal should always be 100% precision. In order to avoid procedures, biopsies and espe- cially unnecessary surgeries, the diagnostic methods’ specificity is crucial. 4, 5

Digital dermoscopy and total body mapping have been used to improve diagnostic accuracy.These techniques allow the evolutionary analysis of suspicious lesions or of the entire tegu- ment of high-risk patients, allowing an early diagnosis of mela- noma that is based on timely, comparative analysis of the same area of the body over time.4

Although they are still used more frequently in research, new imaging methods – such as optical coherence tomography, magnetic resonance and high frequency ultrasound – have been developed for use in dermatology.3, 5 Among these new methods, the in vivo reflectance confocal microscopy (RCM) stands out. Its use has been the most widespread in the major cutaneous oncology centers and, more recently it has been reported in the literature to obtain a resolution similar to histologic examina- tions. 5-9 In Brazil, the broader term “confocal microscopy” has become popular, and can refer to other methods, for different purposes from those described in this study, which in the English-language technical literature is known as in vivo reflec- tance confocal microscopy (RCM).

In vivo confocal microscopy has found space in the many limitations that still hamper the dermoscopic diagnosis of skin cancer, especially achromic or hypopigmented lesions. Some studies have also suggested that the technique can be very use- ful in evaluating surgical margins and determining the best site to perform excisional biopsies, particularly in large facial lesions.1, 9

Next, we will briefly describe the operation of the RCM and discuss the emerging perspectives regarding its use in the daily practice of dermatologic surgeons.