Rare Gastroenterology News

Disease Profile

Giant congenital nevus

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
1-9 / 100 000

3,310 - 29,790

US Estimated

1-9 / 100 000

5,135 - 46,215

Europe Estimated

Age of onset

Infancy

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ICD-10

Q82.5

Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

GPHN; Giant pigmented hairy nevus; Giant pigmented nevus;

Categories

Congenital and Genetic Diseases; Rare Cancers; Skin Diseases

Summary

A giant congenital nevus is a dark-colored, often hairy patch of skin that is present at birth (congenital). It grows proportionally to the child. A congenital pigmented nevus is considered giant if by adulthood it is larger than 20cm (about 8 inches) in diameter.[1][2] Giant congenital nevi can occur in people of any racial or ethnic background and on any area of the body.[2] They result from localized genetic changes in the fetus that lead to excessive growth of melanocytes, the cells in the skin that are responsible for skin color.[1] People with giant congenital nevi may have no other symptoms or may have several symptoms such as fragile, dry, or itchy skin. In about 5% to 10% of the cases the giant congenital nevus is associated with neurocutaneous melanocytosis (excess pigment cells in the brain or spinal cord) and is characterized by neurological symptoms. They also have an increased risk of developing malignant melanoma, a type of skin cancer, especially if the nevus is localized in the vertebral column or when there are multiple associated lesions (satellites).[2]

Whenever possible, treatment includes surgery to remove the nevus. In other cases other treatment such as dermabrasion, shaving or facial excision, chemical peels and laser can be done. In most cases, when there are no neurological problems, the prognosis is good, but it is necessary for the lesions to be examined regularly.[3][4]

Symptoms

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Congenital giant melanocytic nevus
Giant pigmented mole
0005600
30%-79% of people have these symptoms
Generalized hirsutism
Excessive hairiness over body
0002230
5%-29% of people have these symptoms
Cutaneous melanoma
0012056
Hydrocephalus
Too much cerebrospinal fluid in the brain
0000238
Hypopigmented skin patches
Patchy loss of skin color
0001053
Pruritus
Itching
Itchy skin
Skin itching

[ more ]

0000989
Rhabdomyosarcoma
0002859
Seizure
0001250
Subcutaneous nodule
Firm lump under the skin
Growth of abnormal tissue under the skin

[ more ]

0001482
Percent of people who have these symptoms is not available through HPO
Broad forehead
Increased width of the forehead
Wide forehead

[ more ]

0000337
Broad nasal tip
Broad tip of nose
Broad, upturned nose
Increased breadth of nasal tip
Increased breadth of tip of nose
Increased width of nasal tip
Increased width of tip of nose
Nasal tip, broad
Nasal tip, wide
Wide tip of nose

[ more ]

0000455
Congenital onset
Symptoms present at birth
0003577
Deep philtrum
0002002
Everted lower lip vermilion
Drooping lower lip
Outward turned lower lip

[ more ]

0000232
Full cheeks
Apple cheeks
Big cheeks
Increased size of cheeks
Large cheeks

[ more ]

0000293
Hypertelorism
Wide-set eyes
Widely spaced eyes

[ more ]

0000316
Long philtrum
0000343
Narrow nasal ridge
Decreased width of nasal ridge
Pinched nose
Thin nasal ridge

[ more ]

0000418
Nevus spilus
0025510
Open mouth
Gaped jawed appearance
Gaped mouthed appearance
Slack jawed appearance

[ more ]

0000194
Periorbital fullness
Puffiness around eye
0000629
Prominence of the premaxilla
Anterior position of the premaxilla
Anterior position of the primary palate bone
Prominence of the primary palate bone

[ more ]

0010759
Prominent forehead
Pronounced forehead
Protruding forehead

[ more ]

0011220
Round face
Circular face
Round facial appearance
Round facial shape

[ more ]

0000311
Short nose
Decreased length of nose
Shortened nose

[ more ]

0003196
Somatic mutation
0001428

Treatment

Treatment for giant congenital nevus depends on the age of the affected individual as well as the size, location, and thickness of the nevus. Surgery may be done to remove the nevus, particularly when there is a concern that it may develop into a melanoma.[1] When small nevi are removed, the surrounding skin can often be pulled together with stitches. Larger nevi may need to be removed in several stages and full-thickness skin grafts may be needed to help the skin heal following surgery.[1][2] 

When surgery is not possible, other treatment may include procedures such as curettage, dermabrasion, and ablative laser therapy which may be used for superficial skin imperfections, including reducing pigment and hair, but cannot completely remove the nevus.[2][3][5][4] 

Affected individuals should self-monitor and continue to have regular skin examinations to check for benign or malignant tumors. Early awareness will allow their physicians to adjust treatment protocols accordingly.[1] Children are most likely to show neurological signs before primary school and can respond well to a range of symptomatic therapies.[2]

Organizations

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Learn more

    These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

    Where to Start

    • DermNet NZ is an online resource about skin diseases developed by the New Zealand Dermatological Society Incorporated. DermNet NZ provides information about this condition.
    • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
    • Genetics Home Reference (GHR) contains information on Giant congenital nevus. This website is maintained by the National Library of Medicine.
    • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

      In-Depth Information

      • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
        Congenital Hairy Nevi Plastic Surgery
        Congenital Nevi Dermatology
      • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
      • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
      • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
      • PubMed is a searchable database of medical literature and lists journal articles that discuss Giant congenital nevus. Click on the link to view a sample search on this topic.

        References

        1. Congenital melanocytic naevi. DermNet NZ. 2017; https://dermnetnz.org/lesions/congenital-naevus.html.
        2. Kinsler V, Etchevers H & Price H. All About Congenital Melanocytic Nevi. Naevus Global. https://www.naevusglobal.org/naevus-global-english_id93.html.
        3. Giant Congenital Melanocytic Nevus. National Organization for Rare Diseases (NORD). 2013; https://rarediseases.org/rare-diseases/giant-congenital-melanocytic-nevus/.
        4. Hunt R, Shaffer JV & Bolognia JK. Congenital melanocytic nevi. UpToDate. August 23, 2017; https://www.uptodate.com/contents/congenital-melanocytic-nevi.
        5. Schwartz RA. Congenital Nevi Treatment & Management Updated. Medscape Reference. June 05, 2017; https://emedicine.medscape.com/article/1118659-overview.

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