๐ ็ธฝ็ฎ้ ๏ฝ ๐ ่ฑๆๅๆ๏ผๆฌ็ฏ๏ผ ๏ฝ ๐ ๅฎๆด็ฟป่ญฏ ๏ฝ โญ ็ฒพ่ฏ็ญ่จ
Surgery
Surgery
INTRODUCTION
Mohs micrographic surgery (MMS) is a specialized surgical technique that achieves the highest cure rates of any skin cancer treatment, making it the treatment of choice for most skin cancers on the head and neck as well as for recurrent or histologically aggressive lesions. It differs from other techniques in that microscopic margin examination occurs using an intraoperative stepwise approach, thereby eliminating the need to estimate tumor extent. Unlike standard tissue processing, Mohs surgery uses horizontal frozen sections that capture 100% of the peripheral and deep surgical margin in one plane. Residual tumor, if present, is mapped and excised selectively until the entire tumor is removed.
Incorporating meticulous tumor mapping into the removal process requires the surgeon to act in two distinct capacities: as surgeon and pathologist. This further lowers the potential for human error in a situation where tissue orientation is of critical importance. It is well suited for contiguous tumors, most commonly basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), although it is being used more frequently for rarer cutaneous tumors and for melanocytic malignancies (see Chapter 31).
Many studies have demonstrated the efficacy of MMS for the treatment of skin cancer.1โ4 MMS has a 5-year cure rate of 98% to 99% for previously untreated BCC1,3,4
and 94% to 97% for SCC.1,2,5 For recurrent BCC, the 5-year recurrence rate remained lower after treatment with MMS (5.6%) than after surgical excision (17.4%), electrodessication and curettage (40%), or radiation therapy (9.8%).3
Since Mohs surgery allows removal of the cancer with minimal waste and damage to normal surrounding skin, long-term functional and cosmetic results may be optimized. Still, with each procedural step, there is the opportunity for small errors by the Mohs surgeon and lab technician that can be additive, and therefore, strict attention to detail is of critical importance.