Melanoma of the skin is the third most common type of cancer in Australia. It can be deadly, accounting for nearly 3% of cancer deaths. One type of melanoma that can be harder to detect is nodular melanoma. It is often mistaken for harmless skin conditions such as insect bites, acne or blood blisters. And unfortunately, nodular melanoma can grow rapidly and quickly spread to other parts of the body.
Because of its aggressive nature and ability to grow undetected, education on what nodular melanoma looks like and how to prevent it are key to early detection and saving lives.
Here's a guide on how to spot nodular melanoma and when to see a doctor for suspicious moles and skin growths.
- Nodular melanoma is the second most common form of melanoma skin cancer
- It is highly invasive and quickly spreads to other parts of the body
- It can be difficult to detect as it does not meet the 'ABCD' warning signs of melanoma
What is nodular melanoma?
Nodular melanoma is a type of skin cancer. It is an invasive form of melanoma, which arises from pigment cells called melanocytes. Nodular melanoma is considered one of the most aggressive forms of skin cancer. This is because nodular melanomas tend to grow quickly under the surface of the skin and spread into the skin's deeper layers (metastasis). Nodular melanomas comprise 10-15% of melanomas diagnosed in Australia.
Compared to other melanomas, nodular melanomas are usually relatively small in diameter, symmetrical and evenly coloured. Sometimes they lack pigment entirely, appearing skin-coloured or pink. While other melanomas tend to grow outwards, nodular melanomas grow invasively beneath the skin.
Although they are not the most common type of melanoma diagnosed in Australia, nodular melanomas contribute highly to the melanoma mortality rate because of the pace at which they grow and their thickness at diagnosis. If it hasn't spread at diagnosis, the survival rate of patients with nodular melanoma is about 98%. However, if it has spread to other parts of the body, survival rates drop to 22% after 5 years.
Symptoms of nodular melanoma
Nodular melanoma presents differently from superficial spreading melanoma. In fact, a Victorian study of patients with nodular melanoma found the features of nodular melanoma lesions were in contrast to the 'ABCD' warning signs patients and doctors often look for to help diagnose skin cancer. Here are the changes to your skin you should be on the lookout for to help detect nodular melanoma:
- A dome-shaped lump that is often symmetrical.
- It can sometimes be mistaken for a blood blister, acne or an insect bite.
- The lumps or bumps can be black, pink or red but one third are skin-coloured. It is normally a single colour with even pigmentation.
- They are generally larger than other moles on the body.
- Nodular melanoma is often firm to touch.
- The lesion surface can be smooth, or rough and crusted.
- They are likely to itch, sting, ulcerate or bleed after a few months.
Causes of nodular melanoma
Nodular melanoma is caused by a mutation in melanocytes, which give our skin pigment and determine our hair colour. These mutations are commonly caused by damage to the DNA of a skin cell from exposure to ultraviolet light. So frequent sun exposure, sunburn and the use of tanning beds can all cause damage that leads to skin cancers. Genetics are also thought to play a role in the development of melanomas. However, very little is known about what causes these genes to mutate.
Risk factors for nodular melanoma
- A personal or family history of melanoma
- A history of sunburn and sun exposure
- Dysplastic nevi (or atypical mole)
- Having a large number of moles
- Living or growing up in the northern part of Australia
Is nodular melanoma painful?
Skin cancers, including nodular melanoma, rarely cause pain. Therefore, just because a suspicious spot or mole is not causing you physical pain, doesn't mean it's not cancerous.
A study of nodular melanoma patients identifying early warning signs found that visual changes - a darker colour, changes to the shape and rapid vertical growth over a 2 week period - were more accurate indications that there was something "potentially problematic" with a mole or skin growth.
Treatment options for nodular melanoma
As nodular melanoma tends to be quite invasive, the first treatment usually involves a complete excisional biopsy with a 1-2mm margin. If it's detected early enough, this surgery may be the only treatment required. However, because of its aggressive nature, treatments such as targeted therapy and immunotherapy may also be considered, even in the early stages.
If the prognosis is not as positive and the melanoma has spread to other parts of the body, further surgery (to remove lymph nodes, for example) radiation therapy or chemotherapy may be required.
It's also essential that melanoma patients have regular follow-up appointments to detect recurrences and continue to monitor their own skin. A second invasive melanoma occurs in up to 10 per cent of cases.
Skin cancer prevention and care
Because the outlook for nodular melanoma and, in fact, all skin cancers is not as positive if not detected early, prevention is key. Here are some tips to help you avoid skin cancer, particularly melanoma.
- Avoid UV rays by protecting yourself with broad-spectrum SPF 30+ sunscreen, sunglasses and a hat whenever you're outside.
- In men, the head, neck and trunk are the most common sites of nodular melanoma, so be sure to also protect the sensitive skin on your eyes and on your lips.
- In women, nodular melanoma is common on the arms and legs, so be sure to wear long-sleeve shirts and pants when exposed to the sun.
- Make sure you apply enough sunscreen and reapply it regularly.
- Stay out of the sun during the hottest part of the day, from 10am-3pm.
- Avoid using tanning beds.
- Become familiar with your skin and perform regular self-examinations (see below for more tips).
Early detection tips for nodular melanoma
Because the 'ABCD' characteristics of melanoma do not help diagnose nodular melanoma, researchers suggest that 'EFG' - for elevated, firm and growing progressively for more than a month - may be more accurate warning signs to look for in moles and skin growths, increasing the likelihood of early detection.
- Elevated - Is it raised?
- Firm - Is it firm to touch?
- Growing - Is it growing quickly?
Still have questions about skin cancer?
Rapid growth is one of the most helpful clues to diagnosing nodular melanoma during its earliest stage when it's easily treated. For this reason, if a mole, spot or bump doesn't look right or begins to grow rapidly, see a doctor who specialises in skin cancer detection and treatment as soon as you can.
The doctors at SunDoctors perform quick and easy skin checks. Book an appointment online or over the phone by calling 13 SKIN (13 75 46). Alternatively, leave us a message and we will be in contact with you.