Dermoscopy, confocal reflectance microscopy may predict carcinoma in actinic keratosis

Noninvasive diagnostic methods such as dermoscopy and confocal reflectance microscopy may have utility in minimizing biopsy use in predicting progression of actinic keratosis to carcinoma, according to a study.

“Patients with multiple actinic keratosis (AK) have preneoplastic abnormalities constituting the sites of new tumors; this region is called the cancerization field,” Silva A. Rstom, MD, MSc, of ABC Medical School in Santo Andre, Brazil, and colleagues wrote.

Because these locations carry an increased likelihood of developing into malignancy, the researchers proposed that “rigorous evaluation, follow-up and treatment” of these regions may be necessary. However, they acknowledged that noninvasive diagnostic methods such as confocal reflectance microscopy (RCM) may have the capacity to replace repeated biopsies in detecting detect AK, intraepithelial carcinoma (IEC) and squamous cell carcinoma (SCC).

At this time, few data sets describe the nature of AK progression as assessed by concomitant dermoscopy and RCM.

In the retrospective cross-sectional study, the researchers defined morphological patterns and clinical applicability of dermoscopy and RCM assessments of AK lesions and the extent to which they indicate progression to IEC and SCC. The analysis included 30 patients, of which 20 had been diagnosed with AK, six with IEC and four with SCC.

Comparative analysis of dermatoscopic features revealed that erythema was present in all lesions, while three-quarters of lesions demonstrated the red pseudo-network of AK (P = .007) and linear and irregular vessels were observed in 90% of IEC/SCC lesions.

The researchers highlighted the presence of atypical honeycomb in the spinous layer as a key observation from RCM of AK. The honeycomb was typical in the granular layer, according to the findings.

Looking at the IEC/SCC group, irregular epidermal architecture and atypical honeycomb were observed in all epidermal layers. In addition, these malignancies demonstrated a higher prevalence of individual corneocytes and nucleated cells, cellular pleomorphism and nuclear atypia dermal papillae. The researchers also observed irregular vessels within papilla of the IEC/SCC patients, along with cells that had “bright edges and dark central nuclei in the dermis,” they wrote.

From these findings, the group concluded that both dermoscopy and RCM may have use as auxiliary methods for assessing lesions resulting from keratinocyte atypia.

“The results of this study are consistent with published studies and it was possible to propose, with literature support, a model of progression of AK to IEC and SCC,” the researchers wrote.