Biopsy outperforms reflectance confocal microscopy in diagnosing and subtyping basal cell carcinoma: results and experiences from a randomized controlled multicentre trial

Background Reflectance confocal microscopy (RCM) is a noninvasive method for skin assessment, allowing entire lesion evaluation up to the papillary dermis. RCM is a potentially attractive alternative to punch biopsy (PB) in basal cell carcinoma (BCC). Objectives To determine the diagnostic accuracy of RCM vs. PB in diagnosing and subtyping BCC, and to study patient satisfaction and preferences. Methods Patients with a clinically suspected primary BCC were randomized between RCM and biopsy. Conventional surgical excision or follow-up were used as reference. Sensitivity and specificity for BCC diagnosis and subtyping were calculated for both methods. BCC subtype was stratified based on clinical relevance: aggressive (infiltrative/micronodular) vs. nonaggressive (superficial/nodular) histopathological subtype and superficial vs. nonsuperficial BCC. Data on patient satisfaction and preferences were collected using a questionnaire and a contingent valuation method. Results Sensitivity for BCC diagnosis was high and similar for both methods (RCM 99 center dot 0% vs. biopsy 99 center dot 0%;P= 1 center dot 0). Specificity for BCC diagnosis was lower for RCM (59 center dot 1% vs. 100 center dot 0%;P< 0 center dot 001). Sensitivity for aggressive BCC subtypes was lower for RCM (33 center dot 3% vs. 77 center dot 3%;P= 0 center dot 003). Sensitivity for nonsuperficial BCC was not significantly different (RCM 88 center dot 9% vs. biopsy 91 center dot 0%;P= 0 center dot 724). Patient satisfaction and preferences were good and highly comparable for both methods. Conclusions Biopsy outperforms RCM in diagnosing and subtyping clinically suspected primary BCC. This outcome does not support routine clinical implementation of RCM, as a replacement for PBs in this patient group.

Automated summary

The study found that biopsy outperforms RCM in diagnosing and subtyping clinically suspected primary BCC. Patient satisfaction and preferences were good and highly comparable for both methods.