Recurrent basal cell carcinoma in margin-positive tumors.

The purpose of this investigation was (1) to determine the incidence of basal cell carcinoma (BCC) recurrence in patients who had microscopic evidence of residual tumor at the margin of resection and (2) to identify morphological characteristics that predispose to recurrence. Twenty-nine patients with margin-positive BCCs were found in a group of 339 patients who underwent BCC resection. Four patients were lost to follow-up. The remaining patients fell into two groups: 10 patients had their margin-positive tumors re-resected within 2 months and 15 patients were followed until a recurrence developed. The pathology slides of these patients were reviewed and certain features were noted, including histological type, pattern of infiltration, size of tumor, and anatomic site. None of the patients who had re-resection of their margin-positive lesions had a recurrence. All of the patients who did not undergo re-resection developed a recurrent tumor at the site of the original resection. The unexpectedly high rate of recurrence in the latter group may have been a consequence of a disproportionate number of tumors containing sclerosing (morpheaform), mixed (nodular and sclerosing), as well as multifocal (horizontally spreading) lesions. A more aggressive approach to margin-positive BCCs is recommended, particularly if the lesion has sclerosing or multifocal components.