Accuracy of Biopsy in Subtyping Periocular Basal Cell Carcinoma.

Abstract

To determine the accuracy of initial biopsy in the diagnosis of basal cell carcinoma (BCC) histologic subtype. Retrospective histopathologic review of patients with a diagnosis of primary periocular BCC from 2006 to 2013 inclusive. A total of 174 primary BCCs were identified. BCCs were classified as nodular, superficial, or aggressive (including mixed cases with an aggressive component). Punch biopsies were used in 41% of cases, while the remaining patients underwent shave or incision biopsies. The final histologic subtypes at excision were nodular (59%), superficial (7%), nodular and superficial (7%), and aggressive (51%). The overall concordance between the BCC subtype identified in the biopsy specimen and the subsequent excision specimen was 54%. In total, there were 51 cases (29%) of BCC, which included aggressive subtypes, of which 52% of initial biopsies failed to detect an aggressive component. There were 45 cases (26%) of mixed BCC, and an aggressive histologic subtype was present in 73% of these cases. The accuracy of initial biopsy for BCC histologic subtype at excision is highest for nodular BCC. For aggressive BCC, biopsy was able to detect the aggressive component in only 48% of cases. This may have implications for choice of treatment modality.