MOHS Micrographic Surgery

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What is Mohs micrographic surgery?

Mohs micrographic surgery is a highly specialised surgical method for removing certain types of skin cancer. It was developed by Dr Frederic Mohs in the 1930s.
Traditionally, operations for treating skin cancer have involved removal of the affected area (also known as a tumour), along with an area of healthy skin around and below it in order to ensure that the entire cancer has been fully removed. Once removed, the affected area is sent to the laboratory for examination by a pathologist (a doctor who specialises in medical diagnosis by looking at tissue cells under the microscope) to confirm whether the operation has been successful or not. It may take about 2 weeks for the report to become available. If the report shows that the cancer has not been fully removed, a further procedure may be necessary. Also, with this method only a small sample of the margin of the skin cancer can be examined.
With Mohs micrographic surgery, the skin cancer is removed a thin layer at a time with a very small margin of healthy skin around it. Each layer is immediately checked under the microscope by the surgeon. With this method 100% of the skin margin is examined. A further layer is taken from any areas in which the tumour remains, if necessary, until all of the skin cancer has been fully removed. This allows for removal of as little healthy skin around and below the cancer as possible, which keeps the wound as small as possible. This makes it almost certain that the skin cancer is fully removed on the day of the procedure.

Who performs Mohs micrographic surgery?

Only dermatologists or surgeons who are trained in Mohs micrographic surgery can perform this procedure. This training is additional to that required to become a dermatologist or a surgeon. Occasionally, support may be given by other specialists, e.g. a plastic surgeon to reconstruct the wound, or a head/neck surgeon to treat the deep component of the tumour.

What does the procedure involve?

The visible skin cancer is outlined with a marker pen and the skin is numbed with a local anaesthetic injection; you will be fully awake during the procedure. The tumour is then removed with a very small margin of healthy skin around and underneath it. A map of the surgical site and the sections of removed tissue is drawn. This allows the surgeon to know exactly how the removed skin tissue corresponds to the wound so that the correct place for any further surgery can be identified. A dressing is applied and you will be asked to wait whilst the removed skin tissue is examined.
Whilst you are waiting, the removed skin tissue is examined under a microscope to determine whether any of the tumour remains at the edges of the skin tissue that has been removed. It can take approximately 30 minutes for the laboratory to process a small skin tissue sample; a larger sample will take longer. If any of the tumour is seen at the edge, a further layer will be removed from the corresponding area on the skin. This process is very similar to the first stage of surgery; however, the surgeon knows exactly where to find the remaining tumour from the map. More anaesthetic will be injected before surgery.
The process is repeated as many times as necessary until there is no further tumour remaining. Sometimes the tumour can be much larger than is visible at first.

What happens when the entire tumour has been removed?

There are three main options:

At some sites the wound can be left to heal naturally leaving a perfectly good result. If this is done you will be shown how to look after the wound and will be provided with aftercare advice on how to apply or arrange further dressings.
The surgeon may close the wound directly edge to edge with stitches or use a piece of skin from another area as a graft to cover the wound.
The wound may need to be repaired by another surgeon, e.g. a plastic surgeon or an oculo-plastic surgeon (a doctor who specialises in surgery of the eye and face). This is usually planned before you attend your surgery and may be performed on the same day or within a few days. If the repair surgery is at a later date, dressings will be applied and wound care advice will be given. You will be allowed to go home and return for surgery at a later date.

Which conditions can be treated with Mohs micrographic surgery?

Mohs micrographic surgery is most often used for the removal of a type of common skin cancer known as a basal cell carcinoma (BCC). Your dermatologist may also recommend this technique for the removal of other types of skin cancer, for example squamous cell carcinoma (SCC). These skin cancers most frequently arise in the head and neck region where minimising surgical wounds is particularly important in order to ensure a good cosmetic outcome. Mohs surgery is sometimes used for other skin cancers.

Who is suitable for Mohs micrographic surgery?

Mohs micrographic surgery is particularly useful in the following circumstances:
Recurring or previously incompletely removed basal cell carcinomas.
Infiltrative basal cell carcinomas (where the edges of the skin cancer can be difficult to see so traditional methods risk incomplete removal).
Basal cell carcinomas in areas where it is cosmetically better to remove as little healthy skin as possible e.g. eyelids, nose, ears, lips.
Basal cell carcinoma at the site of previous surgery or radiotherapy.
Very large tumours (where removing as little healthy skin as possible can help minimise the size of the wound).

How effective is this treatment?

The cure rate for Mohs micrographic surgery is high for both primary (new) tumours (up to 99%) and recurrent tumours (up to 95%). This compares to a cure rate of approximately 90% for a primary tumour removed by the traditional surgical methods.

Advantages of Mohs Surgery

Mohs surgery is unique and so effective because of the way the removed tissue is microscopically examined, evaluating 100% of the surgical margins. The pathologic interpretation of the tissue margins is done on site by the Mohs surgeon, who is specially trained in the reading of these slides and is best able to correlate any microscopic findings with the surgical site on the patient. Advantages of Mohs surgery include:

Ensuring complete cancer removal during surgery, virtually eliminating the chance of the cancer growing back
Minimizing the amount of healthy tissue lost
Maximizing the functional and cosmetic outcome resulting from surgery
Repairing the site of the cancer the same day the cancer is removed, in most cases
Curing skin cancer when other methods have failed

What are the complications of this treatment?

All surgical procedures carry some risk. For Mohs micrographic surgery the main risks are listed below:

Bleeding / bruising. Bleeding will be stopped during the surgery but can restart afterwards. It is normal to have bruising that may persist for a while. If you take a blood thinning medication, such as warfarin or aspirin, or if you have a medical condition that causes you to bleed more easily, this should be discussed with your doctor before the surgery as it may require additional care during the surgery. It is not always necessary to discontinue your medication but you may be asked to have a blood test before the day of your surgery.

Wound infection: There is a very small risk of developing an infection in your wound. You may be prescribed antibiotics at the time of the surgery if your doctor thinks there is a high risk of infection.

Nerve damage: Small nerves may be cut during the surgery to remove the skin cancer. This can result in numbness which improves over weeks or months as the new nerves grow. Every effort is made to avoid this when removing the tumour; however, in some circumstances it may be unavoidable. Rarely, a nerve that supplies movement to a muscle can be affected resulting in weakness or paralysis of that muscle.

How long will I need to stay in hospital?

Mohs micrographic surgery is a relatively short procedure, which means that you will usually be discharged home on the day of your procedure.
The amount of time that you spend in the hospital on the day will depend on how many layers have to be removed before the skin cancer is fully removed. Another point to consider is how big the tumour is, as very large tumours will take longer to be looked at. You can expect to spend most of a morning or afternoon in the hospital as a general rule.

What should I bring with me on the day?

Find something to occupy your time whilst you await your result. You should inform your doctor of any current medications you are taking, as well as any allergies you may have.

How should the treated area be cared for when I get home?

You will be provided with verbal and written instructions on how to care for your wound.

Are there alternative treatments?

Yes. Before arranging Mohs micrographic surgery, your doctor will explain the alternative treatment options that are available for your type of skin cancer. These may include - traditional surgical skin cancer removal (excision), radiotherapy

Where can I get more information about Mohs micrographic surgery?

http://www.skincancermohssurgery.org
http://www.dermnetnz.org/procedures/mohs.html
http://www.mohssurgery.org/files/public/patient_information_brochure.pdf

Useful Info

Adult Dermatology

We are experienced in the diagnosis and management of a wide range of skin, hair and nail conditions. Some of the more commonly treated conditions include melanoma and non-melanoma skin cancers, acne, eczema, psoriasis, pigmented naevi (moles), rosacea, and various infections. We are also experienced in the management of rarer, more complicated skin disorders.

We regularly provide dermatology consultation services for consultants in other specialties. Our patients benefit from our close working relationship with other specialties. By working closely with other specialties we help provide more thorough care to our patients with skin problems that may relate to other medical conditions.

Paediatric Dermatology

We offer diagnosis and management of a wide range of skin, hair and nail conditions that affect infants, children and adolescents. Some of the more commonly treated conditions include acne, eczema, warts, molluscum and various infections. We also care for children with less common conditions such as alopecia, genetic disorders and others.

We strive to create an environment where your child will feel comfortable. When several treatment options are available we make every effort to choose the least invasive option.

We place a strong emphasis on educating children and their families about skin diseases, skin care and the prevention of lifelong skin damage

Skin Cancer

Both Dr O’Connor and Dr Gibson treat a large number of skin cancers. For most skin cancers, the treatment is surgical. We offer state of the art care including Mohs micrographic surgery (performed by Dr O’Connor) when indicated. In many cases a diagnosis can be made based on clinical appearance. A biopsy may be recommended to confirm a diagnosis. Once the diagnosis has been confirmed, we can discuss treatment options and make recommendations. These recommendations may vary depending on the size and type of skin cancer, the location on your skin, as well as your medical history. There are three main types of skin cancer:

Basal Cell Carcinoma (BCC) is the most common type of skin cancer. Risk factors include history of sun exposure (including childhood exposure) and skin type. People with fair skin are more likely to develop BCC than those with darker skin types but those with dark skin are not immune. A BCC may have several appearances from a pink bump that resembles a pimple, to a white patch with a scarlike appearance, or a sore that won’t heal. They are most commonly seen on sun exposed skin. Though they may become quite large if left untreated, BCCs are not likely to metastasize, or spread to other parts of the body.

Squamous Cell Carcinoma (SCC) is the second most common type of skin cancer. The risk factors are the same as BCC, but also include those with a history of immune suppression, such as a patient with an organ transplant. An SCC may appear as a scaly patch, or a rough bump or nodule that may resemble a wart. SCC may also appear as a sore that will not heal. SCC can be cured if treated early. Though not common, SCC may metastasize if left untreated or if it is a particularly aggressive tumour.

Melanoma is the least common type of skin cancer. However, it is also the most dangerous. Melanoma often appears as a new or changing mole. Those with a family history of melanoma are at increased risk for this tumour, as are those with a history of frequent sunburn, excessive UV exposure including tanning beds, fair skin type and those with many or abnormal moles. The ABCDEs provide a guide for evaluating your moles. If you develop an irregular or worrisome mole, this should be evaluated immediately. If detected and treated early, surgery is curative. If left untreated melanoma may metastasize and be fatal.

Preventative measures can greatly reduce your risk of skin cancer. Practice safe sun!

Minimize exposure between 10am and 3pm when the sun’s rays are strongest.
Wear a broad spectrum sunscreen with SPF 15 or higher every day. This includes cloudy days, rainy days and winter days. Wear SPF 30 plus on sunny days.
Apply a broad spectrum sunscreen 30 minutes before sun exposure. Reapply every 2 hours. Use one ounce (2 Tablespoons) of sunscreen per application.
Wear protective clothing including hats, shirts and sunglasses. Some companies make clothing rated for sun exposure that provide exceptional protection.
Avoid tanning beds! Their use may lead to skin cancer, wrinkles, brown spots and rough skin.
Examine your skin monthly. If you discover a suspicious lesion, contact your GP or Dermatologist.

Useful Info

Excisions

Excision refers to the removal of a lesion by cutting through the skin down to the underlying fat and in most cases repairing the wound with sutures. Many types of lesions are removed by excision, including moles, cysts, lipomas, and skin cancers. When repaired, excisional wounds are usually sutured in a straight line. Sometimes if the lesion is large it may be necessary to repair the defect after excision with a skin flap or graft. Wounds may be closed with a layer of dissolving stitches below the skin in addition to a layer of surface sutures, which are removed one to two weeks after surgery. Depending on the location and size of the wound, it may be recommended that patients use steristrips to support the incisions for two weeks or more following suture removal, until the wounds have sufficient strength to minimize the risk of a spread scar.

All excisions are done using sterile technique and local anaesthesia just around the affected area. . Excisional wounds mature below the surface of the skin for approximately six months following surgery, by which time they have usually reached their final appearance. Taking proper care of the surgical site will help to improve the final appearance of the scar.

Some skin cancers may be treated by excision and curettage. This is usually used for superficial skin cancers. There are no sutures and the skin heals in from the edges. Wound care involves daily cleansing followed by application of an ointment.

Useful Info

Cryosurgery

What is it?

Cryosurgery (or cryotherapy) refers to the application of extreme cold temperatures to treat a broad range of skin lesions and conditions. Liquid nitrogen (at – 196 degrees C) is used and may be sprayed onto, or applied directly to the lesion with a Q-tip or other instrument.

What can it do?

Liquid nitrogen may be used to treat many skin conditions including actinic keratosis (precancers), seborrheic keratosis, warts, molluscum, solar lentigines (age spots) and others. In many instances only one treatment is required. In other cases, such as warts, a series of treatments may be required.

What can I expect with the procedure?

Cryosurgery is a quick procedure that may take a few seconds to a few minutes, depending on the type and number of lesions treated. Most patients find the procedure somewhat uncomfortable but very tolerable. The area will develop a crust that will peel away within one to three weeks. If a blister develops this may be drained with a sterile pin. Paracetamol is recommended for any discomfort.

Are there any side effects?

Most patients experience some discomfort immediately during and after the procedure. This generally fades quickly. Blistering may occur in patients who are very sensitive or when lesions require more aggressive treatment. Treated areas may heal with a spot that is darker or lighter than the surrounding skin.

Mole Removal

Your Dermatologist for a variety of reasons may remove a mole, also called a naevus. If your Dermatologist is suspicious of your mole he or she will recommend that it be removed or biopsied. A black, changing or bleeding mole should not be ignored. This can be a sign of melanoma. Melanoma is the least common, but most dangerous form of skin cancer. If left untreated it can metastasize and lead to death.

Some people choose to have moles removed for cosmetic reasons simply because they consider them unsightly. Your doctor can discuss options for removal depending on factors such as the type and location of the mole. Your mole may be excised and closed with stitches or removed without the need for stitches. Taking proper care of the surgical site will help to improve the final appearance of the scar.

Useful Info

Phototherapy

What is phototherapy?

The term phototherapy literally means the use of light, especially ultraviolet light, to treat medical conditions. Natural sunlight has been known to be beneficial in certain skin disorders for thousands of years, and it is the ultraviolet part of the radiation produced by the sun that is used in phototherapy, in particular the ultraviolet A (UVA) and ultraviolet B (UVB) wavelengths. Patients can be treated with the full UVB spectrum (broadband UVB) or just a small part (narrowband UVB). UVA treatment usually comprises UVA radiation combined with a sensitiser (a chemical that increases the effect of UVA on the skin) called a psoralen (PUVA: Psoralen + UVA). PUVA is also sometimes termed photochemotherapy.

How does phototherapy work?

Ultraviolet light reduces inflammation of the skin and can help in various inflammatory skin disorders. However, although it can cause skin conditions to clear, this is usually temporary and not a cure. PUVA is a more potent form of treatment, so is usually reserved for people who do not respond to UVB.

What conditions can be treated with phototherapy?

Psoriasis is the most common condition treated with ultraviolet light, although a variety of other conditions may benefit, including atopic eczema, other forms of dermatitis, polymorphic light eruption, generalised itching, pityriasis lichenoides, cutaneous T cell lymphoma, lichen planus, vitiligo and many others that are less common (disseminated granuloma annulare, morphoea, etc.).

What does phototherapy involve?

Ultraviolet treatments are usually given in a hospital outpatient department, two to five times a week, in a walk-in cabinet containing fluorescent light bulbs.

The average course lasts between 15 and 30 treatments. The starting dose is worked out by performing a test dose of ultraviolet light on an area of your skin. The first few treatments will often last less than one minute, and the duration of exposure to ultraviolet light will gradually increase, up to a number of minutes.

The amount of skin exposed to the ultraviolet light will depend primarily on the extent of your condition; for most patients all of the skin is exposed to ultraviolet light, except the eyes (which will be protected by goggles) and male genitalia (which should be covered). A visor or face shield may be worn if your face is not affected by your skin condition.

PUVA treatment involves making your skin extra sensitive to UVA by means of a psoralen, which is either taken orally as tablets, 2 hours prior to each treatment session, or by the application of a solution, lotion or gel directly onto your skin (sometimes in a bath – bath PUVA). If a large area of skin is treated with PUVA you will be required to wear sunglasses that will prevent the exposure of your eyes to natural ultraviolet light for 24 hours from the time of psoralen use.

What reasons might prevent you having phototherapy?

If you are unable to attend regularly for treatment.
If you are unable to stand unaided for up to ten minutes.
If your skin condition is made worse by natural sunlight.
If you have xeroderma pigmentosum or lupus erythematosus.
If you have had skin cancer.
If you are taking a medicine which suppresses your immune system, such as ciclosporin.

Your doctor may decide that ultraviolet treatment is not suitable for you if you are very sensitive to sunlight, taking medicines that make you more sensitive to sunlight or if your skin has been damaged by sunlight, sun beds or previous ultraviolet treatments. PUVA treatment may not be used if you have severe liver or kidney disease. PUVA is contraindicated (not recommended) in pregnancy.

Do I need to avoid anything whilst having phototherapy?

Medicines that make you more sensitive to ultraviolet light. You should inform the phototherapy staff of any new medicines prescribed or purchased, including herbal preparations.
Additional sun exposure or the use of sunbeds.
Excessive quantities of foods such as celery, carrots, figs, citrus fruits, parsnips and parsley; these can make you more sensitive to ultraviolet light.
Perfumed products.
Creams, ointments and lotions other than moisturisers, unless directed by the phototherapy staff. • Short haircuts, as they may result in burning of previously covered skin.

What are the potential side effects of phototherapy?

The short-term side effects of phototherapy include:

Redness and discomfort (sunburn).
Dry and itchy skin.
Rashes – a sunlight-induced rash called polymorphic light eruption may develop whilst receiving ultraviolet light.
Cold sores – if you are prone to these it is advisable to cover the area usually affected with sun block when having ultraviolet treatment.
Blisters in areas of psoriasis.
Worsening of skin disease.

Potential long-term side effects of phototherapy include:

Premature skin ageing.
Skin cancer (the risk of skin cancer is related to your total lifetime exposure to ultraviolet light, and other factors such as how easily you burn in the sun; the risk is higher with repeated courses of UVB and PUVA).

Other side effects: using PUVA treatment with psoralen tablets may cause nausea.

Useful Info

Hospital Inpatient Consultations

Both Dr O’Connor and Dr Gibson provide a Dermatology consultation service to patients who are admitted to the Bon Secours Hospital for the inpatient care of medical and surgical conditions. Patients may be admitted with a skin condition as their primary disease or as a secondary problem associated with their primary disease. A skin disorder may be a manifestation of underlying disease and some skin problems occur as a complication of treatment of other disease e.g. chemotherapy. Patients benefit from our close working relationship with consultants in other specialties. By working closely with other specialties we help provide more thorough care to our patients with skin problems that may relate to other medical conditions.