Children can be born with pigmented moles called congenital nevi (or nevus, if singular). These represent a proliferation of melanocytes, the pigment-producing cells of the skin. When they occur, congenital melanocytic nevi can be highly varied in size and shape. They may be very small and insignificant in appearance to very big, covering large areas of the body. Small congenital nevi are those less than 1.5cm in size. Giant nevi are those measuring 20cm or more in size at birth. The goal of giant nevi removal surgery is to remove the mole in its entirety or at least as much as is possible.
A congenital nevus, including giant nevi, are generally considered to occur sporadically, in a completely unpredictable fashion. Small congenital nevi are seen in 1 in 100 births whereas giant nevi occur much more infrequently – 1 in 20,000 births. These moles (also known as melanocytic nevi) are usually brown in color. That color may be uniform or very irregular with darker areas mixed with lighter areas. Congenital nevi can also have thickened or raised areas, texture differences and excessive hair growth. Because excess hair growth is common, these lesions are sometimes alternately referred to as giant hairy nevi. While giant congenital nevi can occur at any body site, there is a predilection for them to appear on the trunk, including back, abdomen, hips and buttocks. The scalp and face are also frequently involved.
Rarely, some children born with giant congenital nevi are found to have deeper involvement of their tissues called neurocutaneous melanosis. The melanocytes involved in this condition proliferated in the brain and spinal cord early in fetal development and typically present with a giant scalp or trunk lesion and many smaller satellite lesions. These children can suffer from increased intracranial pressure, seizures or other neurological problems. An MRI can help to diagnose this condition if it is suspected.
Congenital nevi are believed to have an increased risk of malignant transformation over the lifetime of the child. Small- and medium-sized congenital melanocytic nevi have a risk as low as 1% or less. Large and giant melanocytic nevi have a higher risk of 5-10% over the child's lifetime. As the child reaches puberty, congenital melanocytic nevi can develop additional changes creating a worsened appearance due to thickening, darkening or ulcerations of any part or all of the lesion.
Giant nevi can be challenging to effectively manage. There is often a sense of urgency to remove the external lesion for both medical and cosmetic reasons. The large size of these lesions means they usually cannot be removed all at once in order to allow for primary healing of the excised areas. Many techniques have been developed to provide adequate tissue for closure of the surgical wound that is created by removing the nevi. Most commonly this includes tissue expansion and grafting.
In preparing for giant nevi removal surgery, your plastic surgeon may recommend:
Surgery to remove a giant congenital nevus is typically performed in a hospital or licensed ambulatory surgery setting, and will likely use general anesthesia. Children undergoing surgery will need to be closely monitored at home for healing and general recovery from anesthesia.
Medications are administered to ensure comfort during the surgical procedure. The choices include intravenous sedation and general anesthesia. Your doctor will recommend the best choice for you or your child.
The removal of a giant congenital nevus requires incisions around the edge of the visible lesion, including a small rim of normal tissue to help ensure complete removal. The involved skin will be removed full-thickness through the skin and into the subcutaneous tissues. The lesion will be sent for pathology review to ensure the lesion was benign at the time of excision. If a serial excision is planned, often the central portion of the lesion is removed initially followed by the edges at a later date.
Nevus excisions can be closed with removable or absorbable sutures or staples. Typically several different layers of stitches will be used so only a portion of them may be visible at the end of the surgery, while the rest are hidden beneath the skin. The incision sites will be covered at the end with glue and/or tapes or bandages. Elastic wraps or a splint may be used as needed to further protect the incision sites.
Surgery to remove a congenital nevus will ultimately result in a normal or near-normal contour area without the presence of the large brown lesion. Over time the associated scars will fade. Based on preoperative planning, scars should be placed in such a way as to promote normal growth and function of the involved area.
The success and safety of giant nevi removal surgery start with a consultation with a plastic surgeon and depends very much on your complete candidness.
During your giant nevi removal surgery consultation be prepared to discuss:
Your plastic surgeon will also:
Be sure to ask your plastic surgeon questions. It's very important to understand all aspects of the proposed options for giant nevi removal surgery so you can make an informed decision about which seems best for you or your child's situation. To help, we have prepared a checklist of questions to ask your plastic surgeon that you can take with you to the consultation.
It's natural to feel some anxiety about surgery. Don't be shy about discussing these feelings with your plastic surgeon.
The decision to have a giant congenital nevus removed should be made as part of an informed conversation with an experienced plastic surgeon. Your plastic surgeon will explain in detail the risks associated with surgery. You will be asked to sign consent forms to ensure that you fully understand the procedures you or your child will undergo and any risks or potential complications.
The possible risks of giant nevi removal surgery include, but are not limited to:
These risks and others will be fully discussed prior to your consent. It's important that you address all your questions directly with your plastic surgeon.
Use this checklist as a guide during your consultation for giant nevi removal surgery: