Table 1.

Comparison of the benefits and drawbacks of Mohs micrographic surgery versus wide local excision for melanoma

	Mohs micrographic surgery (MMS)	Wide local excision (WLE)
Benefits	• Equal or improved recurrence and 5-year survival rates vs WLE • 100% of peripheral and deep margins evaluated • Tissue sparing technique • Tumor removal, microscopic evaluation, and repair are performed on the same day (for fresh tissue frozen sections) • Potentially more cost-effective vs WLE • Particularly suited to treat LM/LMM due to high prevalence of subclinical spread	• Considered the gold standard for the treatment of MM and MIS • Long history of success  ○ More data available • Does not require specialized (e.g., fellowship) training to perform • Excision procedure is faster than MMS • Utilizes permanent sections which are considered to be the gold standard for melanocytic lesions
Drawbacks	• Inability to determine the extent of the cleared margins • Interpretation of frozen sections can be tenuous in settings of chronic sun damage, inflammation, and bordering pigmented lesions  ○ Success is dependent on ability of surgeon to evaluate frozen sections • Requires a contiguous growth pattern of the tumor to be reliable • Uncertain role when microsatellites are identified in Mohs layer	• Only 1% of total margins are evaluated with vertical sections • Some studies suggest higher rates of local recurrence vs MMS • Not designed to be tissue sparing • Delay between surgical excision and pathology results  ○ If positive margins found, patient must return for further excision and wait again • May be more costly than MMS

Abbreviations: LM, lentigo maligna; LMM, lentigo maligna melanoma; MM, malignant melanoma; MIS, melanoma in situ.