Mohs Surgery vs. Standard Excision (WLE) - What's the Difference?

Mohs Surgery vs. Standard Excision: A Comparison Guide

When skin cancer (BCC or SCC) is diagnosed, one of the key clinical decisions is choosing the surgical approach. The two most common methods are Mohs micrographic surgery and standard wide local excision (WLE). Understanding the differences will help you make an informed decision together with your treating physician.

“Not every tumor needs Mohs. For a small, well-defined lesion on the trunk, standard excision gives an excellent result. I recommend Mohs when the borders are unclear, when the tumor has recurred, or when every millimeter matters, as on the nose and eyelid.”

What Is Standard Excision?

In standard excision, the surgeon removes the visible tumor along with 4-6 mm margins of surrounding healthy tissue. The tissue is sent to an external pathology lab, and margin results are available after several days. If margins are not clear, a repeat surgery is required.

What Is Mohs Surgery?

In Mohs surgery, the surgeon removes thin layers of tissue one at a time. Each layer is examined under a microscope in real time, where 100% of the margin surface is checked, compared to only 1-5% in standard excision. The process continues until all margins are free of cancer cells.

Comparison at a Glance

Cure rate: Mohs - up to 99% for primary tumors. Standard excision - 90-95%.

Margin examination: Mohs - 100% of margins, in real time. Standard excision - random samples (1-5%), results in days.

Tissue preservation: Mohs - maximal, removing minimal layers. Standard excision - wide margins (4-6 mm).

Number of procedures: Mohs - usually a single procedure. Standard excision - sometimes requires repeat surgery if margins are positive.

Reconstruction: Mohs - immediate, same day. Standard excision - sometimes separate.

Time to results: Mohs - immediate. Standard excision - days to weeks.

What Does the Research Show?

A study published in the Israel Medical Association Journal (IMAJ) by Dr. Kaplan (2025) expands the evidence base for Mohs surgery beyond traditional head and neck indications. The research demonstrates that Mohs surgery is effective for advanced SCC tumors on the limbs and trunk, with improved disease-specific survival rates.

This finding is particularly significant for patients with tumors in areas that were not previously considered a clear indication for Mohs.

Who Is a Candidate for Mohs Surgery?

Mohs surgery is especially recommended for:

Who Is a Candidate for Standard Excision?

Standard excision is an excellent treatment for:

The Advantage of a Certified Mohs Surgeon

It's important to understand that Mohs surgery requires specialized training beyond dermatology residency. Dr. Yehonatan Kaplan completed a Mohs Surgery and Dermatologic Oncology Fellowship at Mount Sinai Medical Center in Miami Beach, an ACMS (American College of Mohs Surgery) approved program.

This training ensures:

Frequently Asked Questions

Is Mohs surgery always better than standard excision? Not necessarily. The choice depends on the tumor type, location, size, and medical history. Each method has its place. The decision is made during a personal consultation.

Is Mohs surgery more expensive? Mohs surgery for BCC and SCC in the head and neck area is included in the Israeli health basket. Maccabi members can have the procedure at Assuta, and Clalit members at HMC with Form 17.

How does recovery from Mohs compare to excision? Recovery times are similar. Most patients return to routine within a few days. The advantage of Mohs is that the wound is usually smaller thanks to maximal tissue preservation.

For more information about Mohs surgery, read the complete Mohs surgery guide. To schedule a personal consultation, contact the clinic.