Congenital Melanocytic Nevus: Risks and Management Options

Congenital melanocytic nevus (mole)

Dear Dr.
Wu,
I have had a black congenital nevus (mole) on my upper back since childhood, which has not shown any significant changes over the years.
Recently, upon closer inspection, I noticed that it is approximately 1.5 centimeters in size, oval but irregular in shape, slightly raised, and has hair growing from it.
Additionally, there are 2 to 3 round lighter spots nearby.
I have always been curious whether this is a birthmark or a mole; I only knew it was there since childhood.
After researching the term "Congenital Melanocytic Nevus (CMN)" and understanding its characteristics, I believe the black spot on my upper back is indeed a CMN.

I would like to ask Dr.
Wu the following questions:
1.
What is the likelihood of a 1.5-centimeter congenital melanocytic nevus on my upper back transforming into malignant melanoma?
2.
Given this, is it necessary for me to undergo preventive excision of the congenital melanocytic nevus, or is it sufficient to continue monitoring it?
Thank you for your guidance, Dr.
Wu.

Axiang, 30~39 year old female. Ask Date: 2020/06/16

Dr. Wu Yuxin reply Dermatology

1.
It's not significant, but it's still advisable to have a physician evaluate it.
2.
It depends on the individual's mindset; if someone tends to worry easily, I would recommend surgical removal.

Reply Date: 2020/06/16

More Info

Understanding Congenital Melanocytic Nevus (CMN) is essential for anyone who has one or is concerned about its implications. A CMN is a type of mole that is present at birth or develops shortly thereafter. These nevi can vary significantly in size, shape, and color, and they can be flat or raised. Your description of a 1.5 cm irregularly shaped, slightly raised, pigmented lesion with hair and surrounding lighter spots aligns with the characteristics of a CMN.

1. Risk of Malignant Transformation: The risk of a congenital melanocytic nevus transforming into malignant melanoma is influenced by several factors, including the size of the nevus. Generally, smaller CMNs (less than 1.5 cm) have a lower risk of malignant transformation compared to larger ones. However, larger CMNs (greater than 20 cm) have a significantly higher risk, with estimates suggesting that the risk of melanoma can be as high as 5-10% or more. For a CMN that is around 1.5 cm, the risk is relatively low, but it is not negligible. Regular monitoring for any changes in size, shape, color, or symptoms (such as itching or bleeding) is crucial.

2. Management Options: The management of a CMN can vary based on its characteristics and the individual’s risk factors. In many cases, if the nevus is stable and shows no signs of change, a "watchful waiting" approach may be appropriate. This involves regular dermatological check-ups to monitor for any changes. However, if there are concerns about the appearance of the nevus or if it shows signs of potential malignancy, a dermatologist may recommend a biopsy or excision.

Preventive excision is often considered for larger CMNs or those that exhibit atypical features. In your case, since the nevus is 1.5 cm and has been stable for years, it may not be necessary to proceed with preventive surgery unless there are changes or concerns raised during examinations. Consulting with a dermatologist who specializes in pigmented lesions can provide personalized recommendations based on your specific situation.

3. Self-Monitoring: It is essential to perform regular self-examinations of your skin, including the CMN. Look for any changes in size, shape, color, or texture. If you notice any new symptoms, such as itching, bleeding, or crusting, it is important to seek medical advice promptly.

4. Genetic Considerations: While most CMNs are sporadic, some may be associated with genetic syndromes, especially larger ones. If there are any family histories of skin cancer or genetic conditions, discussing these with your healthcare provider can provide additional context for your risk assessment.

5. Psychological Impact: Living with a CMN can sometimes lead to concerns about appearance and self-esteem. If you find that your nevus affects your confidence or mental well-being, discussing these feelings with a healthcare professional or counselor can be beneficial.

In conclusion, while your congenital melanocytic nevus appears to be benign based on your description, it is essential to maintain regular dermatological follow-ups to monitor for any changes. If you have any concerns or notice any changes, do not hesitate to consult with a dermatologist. They can provide the most accurate assessment and recommendations tailored to your specific situation.

Similar Q&A

Understanding Nevus: Treatment Options for Large Melanocytic Nevi in Children

Hello Dr. Jiang, my daughter is twelve years old this year. When she was born, she had a brown spot about one centimeter in diameter on her left thigh. At that time, the doctor suggested waiting until she grew a bit older to observe and manage it. Later, when we consulted other d...

Dr. Jiang Yujiao reply Dermatology
Hello: Generally, congenital melanocytic nevi larger than 5 centimeters require attention. If it is only 3 centimeters in size, it can be excised, but please have a dermatologist check it again. You can swim two weeks after the excision. If the dermatologist believes that assista...

Understanding Risks and Treatment Options for Sebaceous Nevus in Children

Hello Dr. Hsiao, I would like to ask about my daughter, who has a coin-sized area on her scalp where hair has not grown since birth. Is this definitely a "sebaceous gland nevus"? I just came across this term online and learned that it is not just a cosmetic issue but s...

Dr. Xiao Kaiwen reply Pediatrics
Sebaceous gland nevi may have a chance of developing secondary malignant or benign tumors, with the occurrence of secondary changes typically happening after puberty. There are two treatment methods: one is laser therapy, and the other is surgical excision. Laser treatment can fl...

Understanding Congenital Nevus: Post-Surgery Care and Scar Management

Hello Dr. Tsai, I have a black birthmark on my neck measuring approximately 6x3 cm², which has been present since birth. It seems to have grown larger as I developed and grew. Concerned about potential malignancy, I decided to consult a plastic surgeon. After discussing with the...

Dr. Cai Xingzhi reply Surgery
Do not use artificial skin; instead, try to use hypoallergenic breathable tape to cover the wound, as it promotes better healing. If there are any issues, please consult a plastic surgeon or a general surgeon for assistance.

Understanding Congenital Nevi in Infants: Should They Be Treated?

Hello doctor, my son is two years and ten months old. He was born with a congenital mole on the back of his thigh, approximately 1x1 cm in size. Should we consider having it removed? Is there a higher risk of it becoming malignant?

Dr. Wu Yuxin reply Dermatology
Without actually seeing the lesion, it is difficult to make a definitive diagnosis. If it is causing significant distress, please seek medical attention promptly.