MOHS SURGERY
Understanding Mohs surgery
Mohs micrographic surgery is a specialized technique performed in a sequence of precise, same-day stages under local anesthesia to examine 100% of tissue margins during the procedure.
Mohs surgery and specialist referral
Both routine excision and Mohs surgery are established approaches for treating select skin cancers. Mohs surgery is not offered locally, so when indicated, referrals are arranged with regional Mohs surgical specialists in Vancouver or Calgary.
Mohs surgery may be used for certain skin cancers, including:
- Some invasive or aggressive basal cell carcinomas
- Squamous cell carcinoma
- Lentigo maligna (a subtype of melanoma), in select cases
The six steps of Mohs surgery
Step 1: Examination & Preparation
The surgeon assesses the area and outlines the treatment site. Local anaesthesia is administered to numb the area completely.
Step 2: Removal of the Top Layer
A thin layer of tissue is removed using a scalpel. Some cancers have deeper extensions not visible on the surface; these are identified through lab analysis.
Step 3: Laboratory Examination
The removed tissue is sectioned, dyed, and mapped. It is then frozen, sliced into thin horizontal layers, placed on microscope slides, and stained for review. This step often takes the most time.
Step 4: Microscopic Analysis
The surgeon examines the edges and underside of the tissue. If any cancer cells remain, the location is marked on the map.
Step 5: Removal of the Next Layer
If needed, another thin layer of tissue is removed from the precise spot where cancer cells were seen. These steps are repeated until no cancer cells remain.
Step 6: Wound Repair
Once the area is cancer-free, the wound is either left to heal naturally or closed with stitches. In some cases, a skin flap or assistance from a specialist (such as a plastic or oculoplastic surgeon) may be required, depending on the location and size of the wound.
Discuss your treatment options
If you’d like to learn more about surgical procedures or evaluate a skin lesion, our team is here to help.