Basal cell carcinoma(BCC) is the most common primary cutaneous neoplasm in Korea. Since the majority of BCCs occur on the head and neck and the goal of the BCC treatment is the complete removal of tumor, Mohs micrographic surgery is ideally suited for maximizing cure rate with minimizing tissue loss.

The purpose of this study is to evaluate the depth of excision as well as the lateral margins of BCC and to correlate these with the clinicopathologic aspects of the tumors.

Twenty patients with 21 BCCs (10 primary, 11 recurrent) diagnosed in the Department of Dermatology of Dong-A University Hospital from March, 1992 through December, 1993 were studied prospectively.

1. Sixty percent of tumors in primary BCCs in our series had a 2-mm maximal margin and 81.8% of recurrent BCC were eradicated with 4-mm or more lateral margin.

2. All the recurrent basal cell carcinomas (8 cases) measuring greater than 15-mm required more than 4-mm margin for the total removal.

3. More than 90% of BCC on the nose in our series required the removal of periosteum/perichondrium or the excision of whole layer.

Mohs micrographic surgery is an appropriate tool to use in proposing guidelines for the treatment of skin cancer because the most accurate method of determining the actual extent of skin cancer can be achieved.