Characteristics of incompletely excised basal cell carcinomas of the skin

Objectives: To determine the proportion of basal cell carcinomas (BCCs) treated by excision biopsy that extended to the margins of surgical excision (incompletely excised tumours) and to identify their characteristics. Design: Case series of BCCs submitted to a single pathologist in the first six months of 1995. Setting: Rural and metropolitan (Perth) Western Australia. Patients: 268 patients with 353 histologically confirmed BCCs. Outcome measures: Age and sex of patients; discipline of referring doctor. anatomical site of BCC; macroscopic features; histological growth pattern; and completeness of excision. Results: Sixteen per cent of BCCs (58/353) extended to the margin of surgical excision. Most of these were situated on the head or neck (43/58; 74%) and were flat (47/58; 81%); a high proportion of incompletely excised BCCs (21/58; 36%) had an infiltrative growth pattern. Recurrent BCCs (28/353; 8%), categorised from the history or because of histologically identified surgical scarring, were even more likely to be flat (26/28; 93%) and to show a microscopic infiltrative growth pattern (18/28; 64%). Seven of the 28 (25%) recurrent BCCs were incompletely excised; all seven were on the head and five had an infiltrative growth pattern. Conclusion: Incompletely excised BCCs are those most likely to recur. Because most recurrent tumours are situated on the head and neck and have an infiltrative growth pattern, we recommend that: Pathologists report on the microscopic growth pattern of BCCs as well as on completeness of excision. Clinicians attempt to excise head and neck BCCs with wide margins initially, where possible. Tumours extending to the margin of excision which are infiltrative in pattern and located on the head and neck may be particularly likely to recur, and immediate re-excision should be considered in these patients.