Histological evolution of recurrent basal cell carcinoma and therapeutic implications for incompletely excised lesions.

Summary Background  It has been proposed that the management of incompletely excised recurrent basal cell carcinomas (BCCs) should depend on their histological appearance, and that nonaggressive recurrent BCCs may not require re-excision. Objectives  To determine the histological evolution of recurrent BCCs. Methods  In a 14-year retrospective study analysing histological sections of recurrent BCCs, 390 specimens from 191 patients were blindly classified by three physicians into aggressive and nonaggressive types according to Sexton's classification. Initial histological sections were available for 33 of the recurrent BCCs. Descriptive analysis was performed. Results  Eight of 33 (24%) recurrent BCCs became histologically more aggressive. Four of 20 (20%) originally nonaggressive BCCs became aggressive during recurrence and four of 13 (31%) originally aggressive BCCs showed a more aggressive component during recurrence. These incompletely excised aggressive BCCs were sited in periorbital and perinasal areas and on the cheek, and were re-excised. Conclusions  Management of incompletely excised nonaggressive BCCs (nodular or superficial types) is still a matter of debate. Previously reported studies have shown recurrence in < 10% of nonaggressive incompletely excised BCCs. Our study showed that rare recurrences of these initially nonaggressive BCCs showed an aggressive component in 20% of cases. These results suggest that initially nonaggressive incompletely excised BCCs do not require re-excision except if they are located in sites with a poor prognosis.