A novel clinical sign to aid in the diagnosis of superficial basal cell carcinoma

Basal cell carcinoma (BCC) is the most common type of skin cancer worldwide. In Australia, BCC represents a significant public health burden. While BCCs have low metastatic potential, they may be locally destructive and therefore, may be associated with considerable morbidity. The diagnosis of BCC is often made clinically and confirmed histologically. Early detection is critical to reduce morbidity. Even for experienced dermatologists, superficial BCCs, which frequently present as erythematous plaques, may elude early detection due to their often subtle clinical appearance. Dermoscopy is a useful in vivo tool to assist with the clinical diagnosis of BCC as it often reveals important morphological characteristics, such as the patterns of cutaneous vasculature. This small, exploratory study of a convenience sample of histologically confirmed superficial BCCs at a private dermatology practice in Melbourne, Australia, demonstrates a diagnostic clinical aid, which has not yet been described.
After stroking the area of a superficial BCC for 10-30 seconds, there is a clinically observable change in the lesional skin, whereby the area becomes pinker in colour and the vascular structures visualised on dermoscopy become more prominent, likely due to a vasodilatory effect in the cutaneous vasculature. The initial and subsequent clinical and dermoscopic images, taken on the same day, were compared by an experienced dermatologist to demonstrate this sign. While this novel clinical sign is not diagnostic or pathognomonic of superficial BCC, it is useful as a diagnostic aid to increase clinical suspicion and thus, it may contribute to a more timely diagnosis.

Dr. Nikki Adler