The rare, congenital disease that causes giant moles: "By age 14, I had been in the operating room 19 times."

Twenty months ago, Alonso, the second son of José and Rocío , a couple from Malaga, was born . At the moment of birth, they were in for a surprise: a dark spot spread across the baby's face . " My God, what is this?" Rocío exclaimed upon seeing him.

At that very moment, the gynecologist who attended the delivery told them what it was: a congenital giant melanocytic nevus . On the third day of life, Alonso underwent an MRI to rule out other conditions . "They told us it could be the tip of the iceberg of another problem, but in the end, it wasn't," they recall.

This disease is a benign skin malformation that is present from birth, hence the name, congenital . "It's a proliferation of melanocytes, the cells responsible for skin pigmentation, which gives rise to one or more pigmented spots, brown or black, which can be of different sizes and shapes. Occasionally, over time, these lesions may develop hair, a rough texture, or surface irregularities. We classify them according to their initial size as small, medium, or giant," Pedro Rodríguez , a dermatologist at the Spanish Academy of Dermatology and Venereology (AEDV), explains to this newspaper.

When they heard the news, Rocío and José were overcome with uncertainty. One thing that helped them a lot was attending the annual meeting organized by Asonevus , the association that brings together those affected by this problem : "You learn about so many stories. We began to see a sense of normalcy from then on; it was encouraging."

They soon referred their baby to La Paz Hospital in Madrid . In fact, in June 2024, doctors offered them surgery to remove it. At first, they were clear about the decision, but over the summer they changed their minds and decided that Alonso wouldn't have to go into surgery after seeing the results on several people. "It would involve about six surgeries, and having it on his face risks distorting his gaze . It wouldn't be a simple scar, but we have the door open to surgery whenever we want."

Although they believe society "is changing," they are concerned about the stares, comments, and nudges. "He's not aware of anything right now, but adults are worse than children. They've even told us , 'What a craving you had during your pregnancy!' They've also asked us if he fell," they say.

In fact, Rocío confesses that she had a hard time : "Now I'm talking about this, but a few months ago it was impossible . I've had to go through grief and I've often thought 'why did this happen to my son?'"

Marta Andreu suffers from a "t-shirt-shaped" nevus that begins at her waist and runs down her arms . This is the opposite, as at 32, she has already had several surgeries under her belt. "The first one was when I was two. I've had several techniques , such as grafts and laser, and by the age of 14, I'd been in the operating room 19 times; I'd had more surgeries than I was old," she tells this newspaper.

"I never saw it as a problem. I had my classmates draw spots like mine on themselves with markers."

Although she and her family are from Torrevieja , they traveled to cities like London and Paris in search of solutions. "Now I only have one on my left arm and satellites (multiple small nevi that spread over the skin)," she admits.

"I never saw it as a problem, not at school either. One kid could use crutches and another wear glasses, so I considered this normal. I had my classmates draw marks like mine on themselves with markers," he recalls.

Now the situation has changed, but Antonia (not her real name) is 59 years old and had a different experience: "I was born at home with a midwife and everyone was surprised to see me. I was the youngest of three sisters and I always had to cover up more because my mother was very worried about being looked at, she made me a swimsuit that went down to my knees , where I have the nevus. This was never talked about at home, it was taboo and at school they never gave me nicknames or teased me."

He didn't find out about his diagnosis until he was 27 : "I never went to the doctor, and once I went for a stroke and they told me what I had. I started investigating and saw that it happened to other people. Since then, I've been going for annual checkups ."

Rosa is 63 years old, from Bilbao, and a member of the board of directors of Asonevus . She had a nevus graft at a center in Madrid when she was two years old. In her case, the nevus occupies part of her torso and back: "If you see me in pants, you wouldn't know."

Unlike Antonia, she never had her sunburn covered, but she was always cautious about the sun . At 19, she consulted a dermatologist, since no one had been able to check her dark spots since her surgery. " I wanted to know if it was hereditary . I remember being a little worried when they told me about the risk of melanoma ; I didn't know," she explains.

According to her, she's never had a bad time aesthetically: "I was more worried about being overweight." The association believes there should be referral centers for families: "It should be easier to refer cases between different autonomous communities." She also points out that obtaining subsidies "is very complicated."

It affects 1 in 20,000 people.

As Dr. Rodríguez points out, congenital melanocytic nevi appear in approximately 1% of newborns worldwide : "This prevalence is similar in Spain ." However, he adds that large nevi are "much less common," estimated to occur in 1 in every 20,000 births . "This low frequency means they are considered a rare condition, which often complicates their management and follow-up," he continues.

Regarding risks, he insists that the vast majority are benign , but some carry an increased risk of developing melanoma, a type of skin cancer. "The larger the nevus, the higher the risk. Furthermore, large congenital nevi can be associated with neurological complications, such as neurocutaneous melanosis, which is the proliferation of melanocytes within the nervous system, in the covering of the brain or spinal cord. This is a rare situation, which occurs especially when there are giant nevi with multiple satellite lesions, and in this situation, there is also a risk of melanoma developing in the nervous system ," he assures.

"In many cases of small or medium-sized nevi, periodic surveillance is chosen without immediate surgical intervention."

Regarding treatment and surgery, he clarifies that it depends on the size, location, and clinical characteristics of the nevus : "In many cases of small or medium-sized nevi, periodic surveillance is chosen without immediate surgical intervention. In cases of large or giant nevi, or if there are suspicious changes in the lesion, surgical removal may be considered. There are also complementary options such as laser treatment to improve the cosmetic appearance, although they do not completely eliminate the oncological risk."

He also describes the types of surgery available : "The most common is simple excision, indicated for small nevi." "For larger lesions , more complex techniques are used, such as staged excision, where parts of the nevus are successively removed; tissue expansion, where skin expanders are used around the skin to stretch it so that when we remove it we can cover the defect; or skin grafts ," he explains.

In La Paz they see 20 to 30 cases a year and most of them do not require surgery.

Regarding the advances, he asserts that functional and aesthetic results, as well as plastic surgery, anesthesia, and technology, have "significantly improved." " The after-effects have been minimized , facilitating faster recovery. Targeted therapies are also being investigated that could, in the future, offer less invasive alternatives based on molecular biology, with oral drugs that can block a mutated pathway and prevent the growth of the nevus, or even promote its disappearance," he concludes.

For his part, Raúl de Lucas , head of the Pediatric Dermatology section at La Paz Hospital, reflects on the aesthetic impact beyond surgery: "We replace a pigmented lesion with scars , and families must have all the information and agree on the treatment with professionals. We see between 20 and 30 giant nevi a year , and most do not require surgery."

Despite this, she acknowledges that childhood is the best time to treat them: "Healing is better and eliminates the stigma before socialization. Children often pick on others because of their physical appearance, and I think we need to address discrimination more than surgery."