lesions.
Data suggest that up to 65% of squamous cell carcinomas (SCCs) were at some point diagnosed as AKs, wrote Jessica G. Labadie, MD, of the department of dermatology at Northwestern University, Chicago, and colleagues. Early identification of AKs is important to prevent progression to SCCs; previous studies have used histology or morphology, but not color, to characterize AK lesions, they said. In the study published in Dermatologic Surgery, the researchers analyzed images and histopathology slides to characterize AKs by color and to examine associations with inflammation and vasculature. They identified AKs from patients diagnosed between January 2018 and October 2019. The lesions were classified as white (4), brown (9), red (15), or pink (21).
Overall, white AKs had an absence of erythema and were significantly less likely to show inflammation on histopathology, compared with other colors. Brown AKs showed no significant increase in vascularity, but were significantly associated with pigment incontinence, basilar pigment presence, and absence of inflammation.
Notably, dermoscopy of red AKs revealed a distinctive polymorphous vessel pattern in most samples, as well as erythema in all. Similarly, all pink AKs showed erythema, and all showed inflammatory infiltrate on histology, although most did not show increased vascularity.
For all colors of AKs, there was a significant association between the presence of erythema on dermoscopy and the presence of inflammation on histology, while the absence of erythema on dermoscopy corresponded to a significant absence of inflammation on histology, the researchers noted.
“This report adds to the armamentarium of a dermatologist by proposing a novel way to characterize AK lesions,” the researchers wrote.
The study findings were limited by several factors including the inability to confirm which AKs would transform into SCCs based on color, and the inclusion of a study population with advanced AKs that may not generalize to typical AKs, the researchers noted. More research is needed to explore the impact of AK color on SCC development, they emphasized.
However, the results represent a novel way to characterize AK lesions, and triage them in a way that may spare some patients from unneeded biopsies, they concluded.
The study received no outside funding. The researchers had no financial conflicts to disclose.