Recurrent basal cell carcinoma after incomplete resection

Backgroud: Because the probability of basal cell carcinoma (BCC) recurrence was thought to be 30% to 50%, surgical tradition became not to perform additional resection when the margin was positive. Objective: To determine whether there is an association among age or sex of the patient, anatomic location, histologic type, or reconstructive procedures and the signs and symptoms of the recurrence, interval between incomplete resection and Mohs micrographic surgery (MMS), or extent of MMS resection. Design: During 20 years, all patients with incompletely excised BCC of the head referred for MMS were sequentially prospectively accrued into the cohort. Setting: An outpatient MMS practice. Patients: Nine hundred ninety-four patients. Main Outcome Measures: Interval to tumor recurrence, interval to MMS, and extent of MMS as determined by mean surface area resected, depth of resection, and number of tumor nests. Results: The interval to signs or symptoms of recurrence and to MMS from incomplete resection was greater for men, patients older than 65 years, those having a tumor on the nose or cheek, those with aggressive or fibrosing BCC, and those who underwent flap reconstruction (P=.001). The extent of MMS resection was greater for those with flap and split-thickness skin graft repairs. The number of tumor nests identified by MMS was significantly greater in those treated with split-thickness skin graft and flap (P=.001). Conclusion: Because it is more difficult to control recurrent BCC, treating tumor remaining at the margin of resection in the immediate postoperative period could result in less extensive surgery.