Dermoscopy-guided surgery in basal cell carcinoma

Background In basal cell carcinoma (BCC), excision margins between 3 and 10 mm, according to site, size, borders, previous treatment and histology, can allow for radical excision in at least 95% of cases. Objective The objective was to ascertain whether dermoscopy can detect more accurately the lateral borders in BCCs than clinical examination alone, and allow us to obtain radical excision in more than 95% of cases with only 2-mm excision margins. Methods A prospective study was performed of 200 consecutive BCCs of the head and neck removed with 2-mm dermoscopically detected excision margins. Morpheaform BCC, deeply recurrent BCC, BCC in Gorlin-Goltz syndrome, BCC located in sites not accessible through dermoscopy and superficial multifocal BCC were excluded. All cases of excised BCC were submitted to a uniform method of histological examination of the whole specimen with serial parallel sections at 2-mm intervals. Results In only three cases did surgical excision with 2-mm margins prove to be inadequate; in the remaining 197 cases, the excision margins were tumour-free. The comparison of clinical and dermoscopic extension measurement showed concordance in 131 cases (65.5%). In 69 cases (34.5%), dermoscopic evaluation showed a larger peripheral extension. Conclusions These results indicate that 2-mm dermoscopically detected excision margins can achieve histologically confirmed complete excisions in 98.5% of cases.