BACKGROUND: Physicians inevitably receive a pathology report after excision of a basal cell carcinoma that indicates that it is incompletely excised. The physician and patient are then left with the dilemma of whether immediate re-excision or close clinical follow-up is indicated.

OBJECTIVE: Our purpose was to identify characteristics of incompletely excised basal cell carcinomas that are at low risk for recurrence.

METHODS: We retrospectively reviewed the charts and pathology slides of all incompletely excised basal cell carcinomas from 1991 to 1994 in a university hospital tumor registry.

RESULTS: Incompletely excised basal cell carcinomas of superficial or nodular subtype, less than 1 cm in diameter, located anywhere except the nose or ears, with less than 4% marginal involvement on the initial inadequate excision had no evidence of tumor persistence.

CONCLUSION: When physicians receive a pathology report indicating the incomplete excision of a basal cell carcinoma, they face the dilemma of further management. The majority of patients should undergo immediate re-excision or Mohs micrographic surgery because tumor persistence was found in 28% of cases. Occasionally, for a small group of select patients, close clinical follow-up may be indicated if the risk of recurrence is very low.