Skin Moles

Moles are the most common lesions of the skin, occurring in all people at an average of 20 skin moles per person. As this is a common and noticeable lesion, and as the cancerous mole develops from the benign mole in the majority if not all instances, it is obvious that the management of skin moles is of great concern. Fortunately, only about one in every million skin moles becomes cancerous. The removal of skin moles has been greatly influenced by traditional teaching based on little, if any, scientific evidence. For example, trauma, acute or chronic, either accidentally or surgically produced, has been blamed for the stimulation of cancerous change in benign skin moles. There is no documented evidence that a previously treated microscopically proved benign mole has become cancerous following trauma of any type. In fact, the evidence that is available concerning the changes that occur in skin moles following partial removal and electrodesiccation with histological observation before and after tends to show that cancerous transformation does not occur.

Also, incisional methods of biopsy of pigmented lesions suspected of being cancerous moles have been considered hazardous because of the general belief that cutting into them increases the tendency to lympatic or hematagenous spread of cancerous cells. Again, there is no documented statistical proof that this occurs. Even a limited excision (that is, an excisional biopsy) of a cancerous lesion does often pass through cancer-bearing tissue (as is sometimes proved by local recurrences
of cancerous moles) and, if the theoretical objection to an incisional biopsy exists, then it should also apply to limited local excisional biopsy. In these circumstances, shave biopsy and electrodessication might be a preferable method of
partial biopsy because of the resultant sealing off of lymphatic and blood vessels. Also, there is no evidence that the inflammation or ulceration of a moles cancer resulting from trauma accelerates the growth of the lesion.

There are four indications for the removal of skin moles. First, the possibility of cancerous change occurring in a mole sometime in the future (a pre-cancerous active junctional mole) and removal is prophylactic as well as diagnostic; second, a suspected cancerous change already present, and removal is again diagnostic and therapeutic; third, cosmetic reasons; fourth, functional and anatomical changes occurring in a mole. The latter reasons, including irritation, trauma and infection, do not predispose skin moles to cancerous change, but removal is often advisable because of the associated nuisance and discomfort. This is particularly true with skin moles in certain areas that are recurrently or chronically subjected to these changes, such as the intertriginous areas, the hairy areas and pressure points under articles of clothing. Hairy skin moles can also be subjected to painful folliculitis, which is often a recurrent and annoying problem.

The method of removal of skin moles not only depends upon the indication for removal, but also the size, the clinical and morphological type, the location and the age of the patient. Even in the best circumstances of clinical evaluation of skin moles by experts, it is very evident that clinical acumen is not sufficient, and pathological examination of all treated skin moles is mandatory. In either of the first two categories, there is a possibility of cancerous or pre-cancerous change occurring; and complete removal or destruction of the mole is therefore essential. Any method of removal may be adopted whereby an adequate biopsy specimen is obtained and the residual mole cells completely removed or destroyed at the time or in the immediate future. Usually, if the lesion is not too large, simple elliptical excision with primary closure of the wound is the removal of choice.

In contradistinction, removal of skin moles for cosmetic or functional reasons does not always necessitate complete removal or destruction of all mole cells. Very often, the best result is produced by shaving off the mole flush with the skin and
then gently electrodesiccating the base. However, many physicians assume that, because the mole has been removed for cosmetic or functional purposes, electrodesiccating or other similar removal of physical type is always the method of choice. Possibly because of a lack of training or inclination, surgical excision is often neglected when it is the best form of removal irrespective of the type of mole or the reason for removal. The morphology of benign skin moles influences the choice of method of removal. A good example is the blue nevus, in which the mole cells are located deep in the dermis and, therefore, a pitted scar is left if the lesion is removed by shave excision and electrodesiccation. It is sometimes difficult to differentiate blue nevus clinically from a cancerous mole, and excisional biopsy is the best form of removal.

The hairy pigmented mole is another example of how gross structure can influence the method of removal. Even though hairs can first be removed by electrolysis and then later the residual lesion removed by shave excision and electrodesiccation
(or comparable methods), it is often simpler to excise the lesion in the first place, thereby producing an equally good cosmetic result. In order to carry out partial shave excision and electrodesiccation and achieve the best result, a lesion should usually have elevation to it; and flat skin moles therefore often lend themselves far better to simple excisional biopsy.

The size of skin moles is a factor in the choice of treatment. Medium to large skin moles are a particular problem, and except for the precancerous active junctional type, are best removed by shave excision and electrodesiccation, or sometimes by piecemeal excisional procedure. Both methods produce a better cosmetic result than reconstructional operation and skin grafting. However, the latter method may be the only one available in the case of very large skin moles, such as the bathing trunk type.

Location of the mole can be a determining factor in the method of removal. Surgical excision of lesions on the back often produces a scar which spreads and is quite unsightly. The same lesion can be removed by shave excision and electrodesiccation with a resultant soft, pliable, smaller scar which does not stretch and usually improves with age. Shave excision and electrodesiccation is the removal of choice of skin moles on the eyebrow, as excisional surgery will remove the hair follicles, thereby reducing or even completely destroying part of the eyebrow. For similar reasons, large skin moles
on the scalp are better treated by shave excision and electrodesiccation.

The controversy regarding whether skin moles on the hands and feet and genitalia should be removed prophylactically still exists. The argument in favor of removal is based on information that shows that the majority, if not all, skin moles in these areas are of the true junctional type; and although the hands and feet only constitute 10.5 per cent of the body's
skin surface, nevertheless approximately 16.5 percent of moles cancers occur in these areas, and of these 80 per cent are on the feet.5"1 This point of view is countered by the various clinical studies showing that approximately one in every six persons has at least one mole on the palm or sole, and therefore prophylactic extirpation of such lesions would be physically impossible.

Subungual skin moles appear to be rare. In one investigation no skin moles were found in a thousand persons studied; but the subungual moles cancer does constitute 3.3 per cent of all moles cancers. Therefore, a subungual pigmented lesion, unless it is obviously due to a benign condition such as a wart or subungual hematoma, should always be excised because of the possibility of its being a cancerous mole.

All skin moles removed should be pathologically examined to determine the type of mole. Occasionally, clinical errors are made, and if the lesion proves to be a cancerous mole or a premalignant junctional mole, then the area can be re-excised widely without affecting the ultimate prognosis. Junctional changes are obviously not in themselves a reason for re-excision, as most skin moles, even those that are clinically obviously intradermal in nature, contain some junctional changes. It has been found, that usually within one year following partial excision and electrodesiccation of skin moles, there is increased junctional activity and pigment formation. Our work so far shows that these changes usually decrease after one year. The clinical importance of this is that sometimes pigment reforms at the site of removal, and that in time may get less or even disappear. If this recurrence of pigment is unsightly or unacceptable to the patient, it can again be removed by shave excision and electrodesiccation. The occurrence of this pigment is fairly common, and its presence should not be, in itself, a sign for wide surgical excision of the area. It occurs more commonly in younger persons and in the more darkly pigmented lesions, and again in lesions which pathologically prove to have a good
deal of junctional activity. To avoid recurrence of the pigmented lesions in such individuals, surgical elliptical excision is often the removal of choice rather than shave excision and electrodesiccation.

Partial removal of skin moles by shave excision and electrodesiccation (or similar methods), accompanied by pathological examination, is the removal of choice for certain benign skin moles, depending on morphologic features, size, and location. Active junctional skin moles and suspected cancerous moles should be removed in their entirety, preferably by excisional operation.