Surgical analysis and biological behaviour of 2277 basal cell carcinomas

A total of 2277 basal cell carcinomas (BCC) treated by surgical excision over a twenty-year period has been followed and analysed into clinical and histopathological type. This paper documents the incidence of different BCC types and points to the importance of the infiltrating, morphoeic and multifocal types. Many BCC are of one homogeneous histopathological type, although others have important secondary characteristics which may not be obvious clinically. We reserve the use of the word 'infiltrating' for BCC types which show microscopically the following characteristics: areas with lack of palisading; small cell clumps; and spiky thin cords of cells projecting out with loose stroma. These may penetrate far and wide along tissue planes and nerves, producing recurrence and spread, despite apparently adequate excision. The infiltrating BCC may also occur secondarily with other primary BCC types, accounting for their--at times--unexpectedly severe effects.