Reflectance Confocal Microscopy for Monitoring Treatment Response in Superficial Basal Cell Carcinoma: Diagnostic Challenges Due to Scar Formation.

Background: Reflectance confocal microscopy (RCM) criteria for in vivo diagnosis of unperturbed basal cell carcinoma (BCC) lesions have been validated and studies have reported high diagnostic sensitivity. However, a paucity of data remains regarding preservation or changes in RCM features after biopsy or treatment.

Objective: Prospectively image biopsy proven superficial BCC (sBCC) with RCM at baseline and 12 weeks post-treatment to determine clearance and identify any associated RCM features.

Methods: Ten subjects with biopsy proven sBCC completed this study. Clinical examination, dermoscopy, and RCM imaging were performed at baseline, prior to treatment, and 12 weeks post treatment with a 1064 Nd-YAG laser. Following treatment, RCM features were compared to clinical and histologic findings.

Results: Statistically significant changes in RCM features at baseline and follow-up included: tumor islands with hyperreflective aggregates, dark silhouettes, peripheral palisading, peritumoral clefting, and dermal inflammatory cells. Changes in nuclear streaming, fibrosis, and vasculature were not significant.

Limitations: A limitation of this study is the small sample size.

Conclusions: The features of nuclear streaming, fibrosis and dilated vessels may be observed during RCM imaging of biopsy proven BCC at baseline and post treatment, and should be cautiously interpreted. Additional studies are needed to further validate these findings.