Incompletely Excised Basal Cell Carcinoma: Residual Tumor Rates at Mohs Re-Excision

Background Basal cell carcinoma (BCC) is the most common skin cancer, and incompletely excised BCC is a commonly encountered clinical scenario. Objective To investigate the incidence of histologic and clinical evidence of residual BCC at Mohs micrographic surgery (MMS) for the treatment of incompletely excised BCC. Methods and Materials One hundred incompletely excised BCCs, from our practice and referred to our practice by local family doctors, treated using MMS between 2005 and 2007 were studied. Patient data included sex, age, anatomic location of tumor, histologic subtype, margin involved, initial closure and closure after MMS, and Mohs stages required for histologic clearance. Results Sixty-nine percent of incompletely excised BCCs had residual tumor at MMS re-excision, and 12% had clinically evident residual disease. Conclusion Immediate re-excision using MMS is recommended for treatment of incompletely excised BCC because the majority of cases have histologically detectable BCC. Watch and wait advice could lead to significant morbidity because recurrence may necessitate more extensive closures and costs. Long-term follow-up is recommended. It is important to conduct self-audits of incomplete excisions and follow up these patients.