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Congenital Melanocytic Naevi

Congenital naevi are common birthmarks arising in one in a hundred births. The majority are classified as small, namely less than 1.5 cm in diameter. The risk of skin cancer or melanoma in small lesions are infinitely small. Most dermatologists agree they have no increased risk of cancer as compared to normal moles. If you are in-doubt about the diagnosis, or paediatric dermatologists at Cutis can provide reassurance. 

Key Points

  • This birthmark is common
  • As the name suggests it is usually present at birth
  • Small congenital moles have no increased risk of skin cancer
  • They are best followed up with serial photography & dermatoscopic examination
  • Excision can be considered in cases where there is cosmetic concern
  • This type of birthmark has poor permanent clearances with lasers

Congenital Melanocytic Naevi at a glance

Best outcomes: Variable
Procedure time: NA
Duration of results: Permanent if surgery
Back to work: NA
Recovery: NA
Anaesthetic: Local
Your specialist: Dermatologist
How much: $ Medicare

Our results speak for themselves


How do dermatologists manage congenital moles?

The short of it-


  • If they are small & not cosmetically significant- observe or watch.
  • If they are in cosmetically sensitive places (eg. face)- excise after 12 yo.
  • If they are really huge- closely watch with photos & frequent examination.


The algorithm is more complex as there are emotional issues, compounded by parental worries, patient factors, genetic risk factors of melanoma & more. If you require reassurance, book an appointment with our paediatric dermatologists at Cutis Dermatology, Brisbane.

How are congenital naevi classified & why is that important?

A simple classification used by dermatologists goes like this.


  • A small congenital melanocytic naevus is < 1.5 cm in diameter.
  • A medium congenital melanocytic naevus is 1.5–19.9 cm.
  • A large or giant congenital melanocytic naevus is ≥ 20 cm in diameter.

The larger the congenital nevus, the higher the risk of melanoma. Small lesions have no increased risks, though some papers quote <1% risk- hence the term no increased risk as compared to other moles. Large or giant lesions have a lifetime melanoma risk of 2-7%, again depending on the literature.

Should you see a dermatologist if you are unsure?

To put your mind at rest, you may want to consider seeing one of our paediatric dermatologists at Cutis Dermatology. Dr Heba, Dr Esh or Dr Devita can review your case & provide you with a firm diagnosis. In most cases we provide serial photography & documentation, including a dermatoscopic examination.

How common are congenital melanocytic naevi?

  • Small congenital naevi occur in 1 in 100 births
  • Medium congenital naevi occur in 1 in 1000 births
  • Giant congenital melanocytic naevi occur in 1 in 20,000 live births

What does surgery entail?

Surgery is the definitive method of treatment, meaning once the birthmark is out, it does not recur. It is the preferred method of treatment as it also obtains pathology for testing. If your birthmark is too large for surgical intervention your dermatologist may-


  1. Undertake serial excision
  2. Refer you for tissue expanders
  3. Discuss methods for debulking the lesion

When should parents consider excision?

If the mole is not conspicuous, most cases do not require excision. If the birthmark is growing in proportion to the child, the usual practice is not to remove it until the child is old enough. Most elect excision around 12 to 16 years of age. If it is not in a cosmetically sensitive place, most are not excised.

Can lasers treat congenital melanocytic naevi?

Yes & no. Lasers have been shown to reduce the size of these birthmarks, however invariably they recur. We believe that lasers, if contemplated, should be performed in a tertiary hospital, solely due to the cost incurred in private practice & the fact that remission is short lived. As a guide-


  • CO2 lasers such as the Ultrapulse have been effective
  • 8-15 sessions are required
  • Healing time ranges from 6 to 14 days
  • Cost is not subsidised by Medicare & starts at $990 per session
  • Side effects include scarring & infection
  • Remission ranges from 12 to 48 months

How often should you get your birthmark checked?

It depends on your risk factors, including the size of the birthmark, subtype & any family history of melanoma. For small congenital moles, most dermatologists will not bring you back for skin checks as they have no higher risk of cancer as compared to normal moles.


Your dermatologist will discuss screen measures including photography, measurement & documentation.

What are other birthmarks that resemble congenital moles?

The most confused birthmarks that resemble mole include a Cafe Au Lait Macule or CALM, normal junctional & compound naevi & epidermal naevi.


CALM birthmarks are usually tan in colour & completely flat. They arise at birth & grow with the child. They are not associated with any risks of cancer &, unlike congenital nevi, respond well to laser therapy.


Epidermal naevi can sometimes resemble congenital melanocytic naevi, however in most cases your dermatologist can tell them apart. Much like moles, epidermal naevi extend deep into the dermal layers of skin. Excision is curative.

What is a naevus spilus birthmark?

This common birthmark has the hallmarks of both a Cafe Au Lait Birthmark & junctional – compound moles. Hence it has flat tanned features interspersed with slightly raised darker dots.


The risk of cancer is very slim, however speckled lentiginous nevi or nevus spilus birthmarks should be monitored. It is up to your treating dermatologist as to whether these birthmarks are observed (majority of cases) or treated. Lasers are extremely unpredictable in removing speckled lentiginous nevus.

Why don’t dermatologists laser moles?

Because it’s not the correct thing to do. As compared with cosmetic GPs, dermatologists are against laser treatment for moles, primarily because we understand histology. 


Lasers can evoke what is known as a pseudomelanoma, meaning microscopic changes that mimic a melanoma. If this happens, there goes your life insurance policy, plus the need for a.) a bigger excision, & b.) close follow up as per melanoma.


Having said that, some dermatologists may laser moles if your risk factors are extremely low (ethnic patients), nevertheless it requires some understanding prior to laser.


Medik8 Physical Sunscreen SPF50+

Dermaceutic All Things Pigment 21 Day Kit

Lasers have been shown to reduce the size of these birthmarks, however invariably they recur. We believe that lasers, if contemplated, should be performed in a tertiary hospital, solely due to the cost incurred in private practice & the fact that remission is short lived.


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