Do we pay attention to our moles? Perhaps because moles usually develop in our childhood or adolescence it has already become such a mundane spot on our body that we are less mindful of its appearance. This article, however, serves to explore the key differences between atypical moles and melanoma and how atypical-looking moles can, in fact, be the manifestation of certain types of skin cancers. Possibly, it can provide the impetus for you to check out your own moles now.
Types of Skin Cancers
There are 3 main types of skin cancers, namely basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and melanoma. The aforementioned types of skin cancers are all malignant in nature and can be categorised into 2 broad categories — melanoma and non-melanoma.
Melanomas are aggressive and have a high potential of spreading to other parts of the body. On the other hand, non-melanomas behave more benignly and have a low possibility of spreading to other parts of the body. BCCs and SCCs fall under the category of non-melanoma skin cancers, while melanomas, as their name suggests, belong to the melanoma category.
Basal Cell Carcinoma (BCC)
Basal Cell Carcinoma
BCCs arise from basal cells, whereas melanomas arise from melanocytes, which are pigment-producing cells. Basal cells and melanocytes are all found in the most superficial layer of our skin — the epidermis. Pre-cancerous lesions develop and manifest as atypical moles when the cells (basal, squamous or melanocytes) encounter some form of damage to their DNA [1]. When this occurs, vital cell-signalling processes that tightly control the proliferation of these cells go haywire as well. Eventually, this culminates in the uncontrolled growth of cells (basal, squamous or melanocytes), which raises the possibility of these accumulating abnormal cells becoming malignant.
Squamous Cell Carcinoma (SCC)
Squamous Cell Carcinoma
Similar to BCCs, SCCs are a type of skin cancer that originates in the epidermis, but they arise from squamous cells rather than basal cells. These cells are flat, scale-like cells that form the outermost layer of the epidermis. SCCs sometimes appear as persistent open sores and other times mimic the look of warts. While these growths can arise in any area, they tend to appear more frequently in those exposed to sunlight. Although SCCs are less common than BCCs, they can be more aggressive and have a higher potential to spread to other parts of the body if left untreated.
Melanoma
Melanoma
Often, melanomas manifest as an atypical mole. On the other hand, BCCs tend to manifest as a flesh-coloured or pearl-like bump, while SCCs frequently appear as a red, firm bump or scaly patch on the skin. Having said this, however, BCCs and SCCs can also manifest as atypical-looking moles as well. As such, it is prudent for us to be keeping an eye on the moles on our bodies.
What is an Atypical Mole?
Atypical moles stand out from their common counterparts due to their distinctive appearance and microscopic irregularities. These unusual moles can appear anywhere on the skin, and while they are not cancerous, they warrant closer observation as the presence of atypical moles could increase an individual’s risk of developing melanoma.
Difference Between Atypical Mole and Melanoma
While atypical moles share some similarities with melanoma, there are key distinctions that help differentiate between the two. To help identify potentially cancerous moles, dermatologists often use the ABCDE Melanoma Recognition Guide as a tool for evaluating moles and determining whether further investigation is needed.
| Feature & Description | Common Mole | Melanoma | |
|---|---|---|---|
| A | Asymmetry (one half of the mole does not match the other half) | Symmetric | Asymmetric |
| B | Borders of the lesion are irregular, ragged, notched, or blurred | Smooth border | Irregular border |
| C | Colour of the lesion is not uniform throughout | Uniform colour | Heterogeneous colour |
| D | Diameter of the lesion is greater than 6mm | Diameter <6 mm | Diameter >6 mm |
| E | Evolving or elevating (lesion changes in size, shape, or colour) | Stable | Evolves within months or years |
What Can Atypical Moles Tell Us?
Atypical moles may very well be pre-cancerous[2] lesions! These lesions are areas of abnormal cell growth that have the potential to develop into skin cancer. While not all pre-cancerous lesions may progress to cancer, they could signal an increased risk, making regular mole screenings crucial to monitor them closely.
When Should I Be Concerned About An Atypical Mole?
There are several points of consideration that should ring alarm bells for us to check out atypical moles that we find. These include symptoms such as bleeding, pain, swelling and itch. Apart from these warning symptoms, there are a few risk factors for skin cancer, which, if present, should raise our index of suspicion that the atypical mole is cancerous. Namely, they are:
- Fair skin [3] (especially those who freckle or sunburn easily)
- Positive family history of skin cancer
- The development of freckles in childhood
- Albinism
- Being under immunosuppressive therapy [4]
- Environmental factors such as excessive exposure to ultraviolet radiation which can come from sun rays or the radiation from tanning booths.
In the presence of any of the above risk factors and an atypical-looking mole, it is best to bring it to the attention of a professional clinician. This way, early diagnosis can be made and timely treatment given so as to minimise the risk of the pre-cancerous or cancerous lesion progressing to life-threatening stages.
How is a Cancerous Mole Diagnosed?
A proper consultation with a relevant medical professional, such as a skin cancer specialist, is necessary. The diagnosis of a cancerous mole usually involves a few steps. These include taking relevant history, a physical examination, and, if necessary, performing a biopsy of the mole.
During history taking, pertinent questions surrounding the suspicious skin lesion will be brought up, such as when it was first sighted, how it has evolved over time, the presence of risk factors for skin cancer, and also if the patient has a positive family history of skin cancer. This aids in either raising or lowering the clinician’s index of suspicion for the disease.
As for the physical examination bit, clinicians will be examining the mole(s) to pick up the presence of aforementioned abnormalities such as asymmetry, irregular borders, varied and irregular colours and large diameter.
Sometimes, it is difficult for the clinician to safely rule out malignancy, and hence, a dermatoscope may be used. This is a handheld magnifying device that allows the clinician to visualise the moles in terms of their colours, depth, and internal skin structures. This way, the features of the mole are made more prominent, and a more accurate identification can be made.
Following this — unless the doctor can completely rule out a malignant lesion — they typically recommend doing a skin biopsy of the suspicious lesion in order to test if this lesion is cancerous and to also reveal the type and subtype of skin cancer. Apart from doing a skin biopsy, doing a biopsy of the patient’s lymph nodes is also important if the doctor suspects that the cancer has spread.
Treatment Options for Pre-cancerous and Cancerous Moles
Currently, there are several options available when it comes to treatment plans for individuals with pre-cancerous or cancerous moles. They can broadly be categorised into surgical and non-surgical procedures. Whichever plan of action is taken in the end is determined by the site, size, type stage of the lesion and a few patient factors.
Surgical Excision
Surgical excision, on the other hand, is preferred when the cancerous lesion is considerably big. It is a procedure which involves surgically removing the entire cancerous lesion, as well as a little of its peripheral healthy tissue, in order to ensure complete removal of cancerous cells.
MOHS Micrographic Surgery
Last but not least, Mohs micrographic surgery is another treatment option and sometimes regarded as the gold standard for surgical treatment of cancerous moles. In this surgery, thin layers of cancer cells are repeatedly excised and subsequently observed under the microscope until no more cancerous cells are found.
A potential benefit of this procedure over the other options is the minimisation of unnecessary removal of healthy tissue and in so doing, also does not compromise on the complete removal of cancerous cells from the patient.
Mohs surgery is commonly highly recommended for recurrent skin cancers and moles with irregular borders, which impedes complete excision of the mole. This procedure also potentially leaves the most cosmetically appealing results because it promises to have minimal scarring. As such, if the site of the mole of interest is on the face for example, this is a suggested treatment option. Often, Mohs microsurgery is usually followed up by radiation therapy.
Radiation Therapy
Radiation therapy, for one, is a better choice for patients who are unable to undergo surgery for various reasons. Additionally, pharmacological agents such as iplimumab, nivolumab and trametinib, imiquimod and fluorouracil are FDA [5] approved drugs for immunotherapy.
While there are many possible courses of action for one to take, there is always a risk of recurrence. This is especially so for cancerous lesions that occur in the nose region. Furthermore, it is prudent to note that an individual has a heightened risk of developing other forms of skin cancer once you are diagnosed with one.
Early Detection is Key
The prevalence of skin cancers is rapidly increasing. Not only does it bring with it devastating impacts on one’s quality of life and, for some, death, but it also places a considerable burden on healthcare services.
As such, there are some precautions and habits that one can cultivate in order to reduce the risk of getting skin cancers. Some of them include minimising exposure to the sun, not frequenting tanning booths, and using sunscreen to protect oneself from ultraviolet radiation.
It is also advisable to have a heightened awareness of unusual skin changes and atypical moles but not worry excessively. Should there be any suspicious skin lesions, it is always wise to bring it up to a relevant medical professional and seek a consultation and treatment for it promptly.
References:
- Board, P. A. (2017, August 28). Skin Cancer Treatment (PDQ®). Retrieved 3 February, 2019, from https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0032519/
- Liu, Y., & Sheikh, M. S. (2014). Melanoma: Molecular Pathogenesis and Therapeutic Management. Retrieved May 24, 2018, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4346328/
- Goldberg, L.H., & Lebwhol, M. (n.d.). How to Spot an Atypical Mole. How to Spot an Atypical Mole. Retrieved 3 February, 2019, from http:// skincancer.org/skin-cancer-information/atypical-moles/warning-signs-and-images
- “Atypical, Abnormal, and Irregular Moles: Is Your Mole Normal?” WebMD, WebMD, webmd.com/melanoma-skin-cancer/skin-mole-normal#2.
- “Atypical Moles.” Palmoplantar Pustulosis – American Osteopathic College of Dermatology (AOCD), aocd.org/page/AtypicalMoles.
- Watson, Stephanie. “Typical vs. Atypical Moles: How to Tell the Difference.” Healthline, Healthline Media, healthline.com/health/managing-skin-cancer/typical-vs-atypical-moles#4.
