Dermatoscopy of facial actinic keratosis, intraepidermal carcinoma, and invasive squamous cell carcinoma: a progression model.

Background: Little is known about the dermoscopic features of keratinocyte skin cancer.

Objective: We sought to determine the dermoscopic features of facial actinic keratosis (AK), intraepidermal carcinoma (IEC), moderately to poorly differentiated invasive squamous cell carcinoma (SCC), and well-differentiated SCC of the keratoacanthoma type.

Methods: This was a retrospective analysis of dermoscopic images of histopathologically diagnosed keratinocyte skin cancer.

Results: A total of 243 (70 AK, 71 IEC, 78 SCC, and 24 keratoacanthomas) tumors of the face from 243 patients (mean age: 71.1 years; range: 44-94 years) were analyzed. The majority of patients had a fair skin type, history of melanoma or nonmelanoma skin cancer, and multiple AK. A red pseudonetwork was significantly associated with AK (P < .001), whereas dotted/glomerular vessels, diffuse yellow opaque scales, and microerosions were significantly more prevalent among IEC (P < .001). Hairpin vessels, linear-irregular vessels, targetoid hair follicles, white structureless areas, a central mass of keratin, and ulceration were significantly associated with invasive SCC (P < .001 for all criteria). Similar patterns as in SCC were observed among keratoacanthomas.

Limitations: The retrospective design of our study and the lack of assessment of sensitivity and specificity of the dermoscopic criteria are limitations.

Conclusions: Based on our findings we propose a progression model of facial AK developing into IEC and invasive SCC.