Positive margins in basal cell carcinoma: relationship to clinical features and recurrence risk. A retrospective study of 248 patients

BACKGROUND: Incomplete resection of a basal cell carcinoma does not necessarily imply tumour recurrence. OBJECTIVE: The purpose of our study was to determine the clinical features most often associated with positive surgical margins and to establish whether positive margins effectively imply tumour recurrence. METHODS: We did a retrospective evaluation of 273 basal cell carcinomas in a total of 248 subjects. For each case, data regarding tumour location, sex, histological type and the presence or absence of affected surgical margins were collected. Follow-up was available in 151 cases. RESULTS: Positive margins were most often observed in facial lesions, particularly in the nasal and perioral areas, and for morphoeic histological types. Tumours with margin involvement exhibited a higher recurrence rate (26%) than those with free margins (14%) over a 5-year follow-up period. CONCLUSIONS: Individualized management, with special considerations depending on tumour location and histological type, is needed to treat basal cell carcinomas and cases with affected margins. Re-excision, preferably with Mohs' surgery, is advised in the latter as recurrences are much more complicated to treat. Furthermore, all cases need adequate follow-up, even in cases with unaffected surgical margins.