The diagnostic value of in vivo reflectance confocal microscopy in actinic keratosis

Abstract

Background Actinic keratosis (AK) is a pre‐neoplastic skin damage caused by sun exposure with a risk of transforming squamous cell carcinoma (SCC) ranging from 0.1%‐20%, while it should be differentiated with many diseases such as seborrheic keratosis (SK), discoid lupus erythematosus (DLE), Bowen's disease, and basal cell carcinoma(BCC) et al. Reflectance confocal microscopy (RCM) as a non‐invasive method is showing an increasing diagnostic accuracy. Currently, there are a few studies that summarized the characteristics of AK with RCM. Aim The study aimed to find the diagnostic value of diagnosing actinic keratosis by reflectance confocal microscopy. Methods A total of 92 patients with clinical suspicious diagnosis of actinic keratosis were enrolled in this study, and RCM device imaged their lesions. Fifty‐three of these patients underwent skin biopsies to confirm the diagnosis. We retrospectively analyzed the results of RCM and histological diagnosis and then summarized the RCM characteristics of biopsy‐confirmed lesions. Results Based on RCM images, 76 of 92 (82.6%) patients were diagnosed with AK, 9 of 92 (9.8%) patients could not be diagnosed by the dermatologist according to RCM. Of all 53 biopsied lesions, 42 (79.2%) were AK, 1 was seborrheic keratosis, 3 were basal cell carcinoma, three were discoid lupus erythematosus, 1 was Bowen's disease, and three were squamous cell carcinoma. Conclusion The value of RCM in the diagnosis and differential diagnosis of AK is good and worthy of clinical application.

Line‐field confocal optical coherence tomography of lentigo maligna with horizontal and vertical histopathologic correlations

“…9,10 In actinic keratosis, LC-OCT shows, similarly to RCM, a variable degree of hyperkeratosis, acanthosis, and cellular and nuclear pleomorphism of keratinocytes, as reported by some studies. 10,[19][20][21] As regards solar lentigo/seborrheic keratosis, although a specific LC-OCT study has not been conducted so far, the expected findings, based on our experience, would be similar to those obtained with RCM, that is, hyperpigmentation of the basal layer, polycyclic papillary contour, bright branching tubular structures, and bulbous projections. 21 Finally, thanks to the integrated dermoscopic camera, LC-OCT may be useful to detect the most appropriate areas for biopsy as well as for surgical margins delineation, and for topical treatment monitoring.…”

“…However, this invasive procedure may be problematic, especially for large lesions of the face in elderly patients with comorbidities, therefore LC‐OCT may be crucial for narrowing down the number of unnecessary biopsies by ruling out other disorders such as pigmented actinic keratosis and solar lentigo/seborrheic keratosis 9,10 . In actinic keratosis, LC‐OCT shows, similarly to RCM, a variable degree of hyperkeratosis, acanthosis, and cellular and nuclear pleomorphism of keratinocytes, as reported by some studies 10,19–21 . As regards solar lentigo/seborrheic keratosis, although a specific LC‐OCT study has not been conducted so far, the expected findings, based on our experience, would be similar to those obtained with RCM, that is, hyperpigmentation of the basal layer, polycyclic papillary contour, bright branching tubular structures, and bulbous projections 21 .…”

A Review of Existing Therapies for Actinic Keratosis: Current Status and Future Directions

“…Among these, dermatoscopy can be used to differentiate AK from invasive cutaneous SCC and to diagnose lesions at an early stage. In addition, reflectance confocal microscopy and high-definition optical coherence tomography may allow the detection of clinically invisible subclinical lesions and monitoring of treatment efficacy [ 23 ]. Biopsy of an AK lesion is recommended in equivocal cases in which differential diagnosis—including basal cell carcinoma, Bowen’s disease, invasive cutaneous SCC, amelanotic melanoma, lentigo maligna melanoma, and superficial seborrheic keratosis—cannot be ruled out with clinical examination and imaging techniques [ 24 ].…”

In vivo reflectance confocal microscopy for monitoring actinic keratosis treated with 5‐aminolevulinic acid photodynamic therapy

“…However, this invasive technology affects patients from a cosmetic point of view and can only examine a lesion of 3-5 mm. Since RCM has two advantages, namely its high accuracy, sensitivity, and specificity in diagnosing AK, 12,13,21,24 and being non-invasive, large-scope and repeatable, 11 applying RCM for monitoring the therapeutic effects of AK is a certain tendency. And several studies had applied RCM in monitoring the therapeutic effect of AK.…”