Mohs process explained in photos

There is an epidemic of skin cancer in the world, and South Africa is no exception. Although the most dangerous skin cancer is malignant melanoma, the most common ones are known as basal cell carcinoma and squamous cell carcinoma, collectively known as non-melanoma skin cancer (NMSC). The gold standard surgical method worldwide for the most effective removal of skin cancer is a technique called Mohs Surgery ("Mohs" refers to the surname of the doctor who first practiced it). With this technique, performed in most cases under a local anaesthetic, the tumor is removed with a thin layer of surrounding healthy tissue. The removed tissue is then processed immediately by the Mohs surgeon in a Mohs histological laboratory on site, while the patient returns to the ward. The specific method of processing allows tissue slides to be produced that shows the whole, complete cut surface around the tumor. These slides are then examined by the Mohs surgeon and will show very accurately any remaining tumour, including the exact area on the tumor wound where tumour is still present. The patient then returns to the day theater and process is repeated, but only on the area of remaining tumour, leaving the healthy tumour-free part of the wound alone. As soon as the Mohs surgery confirms the skin cancer to be completely removed, a specialist reconstructive surgeon or the Mohs surgeon repairs the defect where the cancer was removed almost always on the same day.

Mohs Micrographic Surgery is not required for the treatment of every skin cancer. Patients are seen for Mohs surgery by referral only.
The Skinmatters Mohs Micrographic Surgery unit functions as an extension of the referring Practices. Referring practitioners successfully diagnose and treat the majority of skin cancer With the appropriate methods at their disposal, know the indications and criteria for Mohs Micrographic Surgery, and which patients to refer for this procedure.
Following successful Mohs Micrographic Surgery, all patients are referred back to the Original referring practice, for subsequent follow-up and management of future skin disease.

Mohs Micrographic Surgery by the Skinmatters practice is performed at Life Brooklyn Day Hospital, where the patient arrives on the day scheduled for the procedure.

Admission to the Day Hospital is efficient and friendly. For private patients there is an Option for the Mohs Micrographic Surgery to be performed without an admission to the Day Hospital.

Day ward sisters and staff take care of patients needs during the day.

The skin cancer is excised with the Mohs technique under a local anaesthetic. The patient returns to the ward following the excision.

While the patient returns to the ward, the excised tissue is taken to the Mohs Micrographic Surgery laboratory, on site, where the tissue is mapped and prepared for processing by the Mohs laboratory staff.

A tissue block is embedded in cryogel ready for freezing.

Freezing of the tissue block using specialised equipment called a cryostat.

The frozen tissue block is cut into thin tissue wafers by the histotechnologist in the cryostat.

A tissue wafer ready to be positioned on a histology glass slide.

Glass slides containing tissue wafers are stained with tissue staining dyes, to prepare them for histological examination.

The completed histology slides are presented with the map of the defect to be examined microscopically.

The entire cut surface around the skin cancer is examined microscopically for any remaining tumour. It is this ability that makes Mohs micrographic surgery the most accurate method of removing skin cancer, provides the highest cure rate of any method and distinguish the procedure from any other surgical, medical or radio-therapeutic option.

Tumour still present on the cut surface can clearly be seen on the frozen sections.

Any remaining tumour found is mapped on the Mohs map.

If tumour was found, the patient returns to the procedure room for a next stage of the Excision, still under local anaesthesia. Only tissue containing tumour is removed with Subsequent stages, clear areas are left alone, thereby limiting the size of the defect to the Smallest possible, while achieving maximum clearance of the tumour.

With the patient again returning to the ward, the next stage is processed and mapped, and Histology slides prepared. This process is repeated until all tumour is removed.

Once the microscopic examination finds all cut surfaces to be clear of tumour, the Mohs Micrographic Surgery is completed.

The final phase of the treatment, is closure of the defect. Due to the extent and Location of these complicated tumours, this is usually performed by a specialist Reconstructive surgeon, on the same day. However, if circumstances permit, the Mohs surgeon or referring specialist may elect to do so. The actual defect will be evaluated and the patient prepared for the Reconstructive phase. The professional nursing sister will aid in preparation and discuss the reconstructive process, recovery and post-operative care, in utmost detail
Very commonly the reconstruction is more invasive than the excision. This may necessitate a form of sedation or anaesthetic to facilitate a comfortable procedure. This will be administered by a specialist, based on the patient’s medical condition, the site and extent of the defect.

Most defects are reconstructed Utilizing tissue from the vicinity. Tissue With similar appearance is usually Harvested, with its underlying blood supply. The donor area and movement of these tissue blocks are precisely planned to coincide with natural shadow lines. This minimizes unsightly scars and facilitate the ultimate aesthetic result. These are called tissue flaps. After closure with tissue flaps, there will always be significant swelling and some bruising, combined with some distortion of the surrounding tissues. This settles within a fairly short period. Rarely secondary procedures might be necessary to optimize the cosmetic appearance of these flaps. Once the sutures are removes, the Scars are still slightly pink. The maturation process takes a couple of months, but once the scars fade away, they are usually quite inconspicuous.

Regardless of the actual reconstructive modality, the wounds and donor sites are anaesthetized meticulously with long acting local anaesthetic. Immediately after the procedure, these areas are completely numb and pain free. The local anaesthetic gradually wears off over the following day, providing a fairly comfortable recovery period, with minimal need for analgesics. It is impossible to reconstruct all defect without any scars. The first priority is obviously complete eradication of the tumour. The aim of the reconstruction however, is to provide the patient with an aesthetically acceptable reconstruction, within the shortest possible space of time, to facilitate a speedy return to functional and social activities. 90% of patients have a single stage reconstruction, are discharged on the same day and have an exceptional cosmetic result.

Patients are discharged, and returns home, on the same day. Mohs Micrographic Surgery And Reconstruction is a one-day procedure for most patients.