Rare Hematology News

Disease Profile


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.


US Estimated

Europe Estimated

Age of onset





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


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.


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.


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


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.


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.


Not applicable


Other names (AKA)

Macromastia; Gestational gigantomastia (subtype); Pregnancy-induced gigantomastia (subtype);


Gigantomastia is a rare condition characterized by excessive breast growth. It may occur spontaneously, during puberty or pregnancy, or while taking certain medications.[1][2] There is no universally accepted definition of gigantomastia, but the majority of medical articles refer to a particular weight of excess breast tissue.[3] Symptoms of gigantomastic may include mastalgia (breast pain), ulceration/infection, posture problems, back pain and chronic traction injury to 4th/5th/6th intercostal nerves with resultant loss of nipple sensation. It is also associated with decreased fetal growth, if it occurs during pregnancy.[1]

The exact cause of gigantomastia is not known; however, hormonal and hereditary factors may be involved. Additionally, gigantomastia has been noted as a side effect of treatment with certain medications, such as like D-penicillamine.[4][2] Treatment may include breast reduction, mastectomy with or without reconstruction, hormonal treatment, or a combination of treatments.[1][4]


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:
Percent of people who have these symptoms is not available through HPO
Abnormal thorax morphology
Abnormality of the chest
Sex-limited autosomal dominant


Breast reduction with or without hormonal therapy is often the first line of treatment for women who have gigantomastia. However, recurrence of gigantomastia may occur, requiring a second breast reduction procedure or mastectomy. Mastectomy might be recommended following recurrence of gigantomastia after breast reduction, especially in those patients who have gigantomastia associated with puberty or pregnancy.[1] It is important to discuss this information with a health care provider in order to determine what treatment might be appropriate.


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.

    In-Depth Information

    • 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 Gigantomastia. Click on the link to view a sample search on this topic.


      1. Dancey A, Khan M, Dawson J, Peart F. Gigantomastia a classification and review of the literature. J Plast Reconstr Aesthet Surg. December 13, 2007; https://www.ncbi.nlm.nih.gov/pubmed/18054304.
      2. Kulkarni D, Beechey-Newman N, Hamed H, Fentiman IS. Gigantomastia: A problem of local recurrence. The Breast. 2006;
      3. H. Dafydd, K.R. Roehl, L.G. Phillips, A. Dancey, F. Peart, K. Shokrollahi. Redefining gigantomastia. Journal of Plastic, Reconstructive & Aesthetic Surgery. 2011; 64:160-163. https://www.ncbi.nlm.nih.gov/pubmed/20965141.
      4. Antevski BM, Smilevski DA, Stojovski MZ, Filipovski VA, Banev SG. Extreme gigantomastia in pregnancy: case report and review of literature. Arch Gynecol Obstet. 2007;

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