Validation of dermoscopy as a real-time noninvasive diagnostic imaging technique for actinic keratosis.

OBJECTIVE

To validate dermoscopy as a real-time noninvasive diagnostic imaging technique for actinic keratosis (AK).

DESIGN

Prospective study to validate a diagnostic test.

SETTING

Dermatology department of a tertiary university hospital in Fuenlabrada, Madrid, Spain.

PATIENTS: A total of 178 patients with a clinical diagnosis of AK participated in the study.

MAIN OUTCOME MEASURES: An independent blinded comparison was performed between dermoscopy results and histopathological findings, the gold standard for the diagnosis of AK. All the patients underwent both diagnostic tests.

RESULTS

One hundred seventy-eight lesions were evaluated. The concordance between dermoscopy results and histopathological findings was 0.917. The sensitivity of dermoscopy for the diagnosis of AK was 98.7%, with a specificity of 95.0%, a positive likelihood ratio of 19.74, and a negative likelihood ratio of 0.01. A diagnostic algorithm that combined follicular openings and erythematous pseudonetwork demonstrated a sensitivity of 95.6% and a specificity of 95.0% for the diagnosis of AK.

CONCLUSIONS

The sensitivity and specificity of dermoscopy for the diagnosis of AK were high, as was the concordance between dermoscopy results and histopathological findings. As a real-time noninvasive diagnostic imaging technique for AK, dermoscopy may be incorporated in the management of patients with these lesions.