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Disease Profile

Cutaneous mastocytoma

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

All ages





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)

Cutaneous local mastocytoma; Multiple mastocytoma; Solitary mastocytoma


Blood Diseases; Immune System Diseases; Rare Cancers;


The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.

Orpha Number: 79455

Cutaneous mastocytoma is a form of cutaneous mastocytosis (CM, see this term) generally characterized by the presence of a solitary or multiple hyperpigmented macules, plaques or nodules associated with abnormal accumulation of mast cells in the skin.

Prevalence is unknown but mastocytomas are the second most frequent form of CM in children, accounting for 10-15% of cases.

Clinical description
Patients generally present during infancy, with most presenting in the first three months of life. However, rare cases of onset in adulthood have been reported. Mastocytomas usually appear as oval lesions with red-brown, pink or yellow pigmentation. The diameter varies from around 1-4 cm and the surface may be smooth or have a ''peau d'orange'' appearance. The trunk, face, neck and extremities are the most common sites of involvement. Patients with multiple mastocytomas (up to 5) have been reported with new lesions appearing at different locations up to two months after emergence of the initial lesion. Other skin manifestations may include blistering (most frequent during infancy), pruritus and urticaria. Stroking of the lesions results in Darier's sign and generalized flushing in some cases. Additional systemic symptoms are rarely associated with cutaneous mastocytomas but a few cases with fever, gastrointestinal disturbances (nausea, colic and diarrhea), headaches and asthma-like symptoms have been reported.

Mutations in the KIT gene (4q11-q12) have been identified in some patients with CM, however, this mutation is rare in the pediatric population and the etiology and pathogenesis of cutaneous mastocytoma remains to be determined.

Diagnostic methods
Diagnosis is made on the basis of the clinical appearance of the lesions and the presence of Darier's sign. Histopathological examinations confirm the diagnosis by revealing a dense infiltrate of mast cells in the upper dermis.

Differential diagnosis
The differential diagnosis generally includes melanocytic nevi, xanthomas and juvenile xanthogranuloma (see this term).

Management and treatment
Treatment is symptomatic and includes oral administration of antihistamines, topical steroids and the use of hydrocolloid dressings to cover the lesions. Trigger factors (such as rubbing of the lesions and use of nonsteroidal anti-inflammatory drugs) should be avoided. Surgical excision provides a definitive cure for patients with alarming symptomatic lesions that do not respond to other forms of treatment and has been recommended as a first-line therapy in some cases.

The prognosis for patients with onset during infancy is good with regression of most lesions during childhood and complete resolution by adolescence. Rare cases of persisting mastocytoma in adulthood have been reported. Spontaneous resolution is less common in patients with adult-onset.

Visit the Orphanet disease page for more resources.


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:
80%-99% of people have these symptoms
Cutaneous mastocytosis
Itchy skin
Skin itching

[ more ]

Subcutaneous nodule
Firm lump under the skin
Growth of abnormal tissue under the skin

[ more ]

30%-79% of people have these symptoms
Thickened skin
Thick skin
5%-29% of people have these symptoms
Abdominal pain
Pain in stomach
Stomach pain

[ more ]

Abnormal blistering of the skin
Blistering, generalized

[ more ]

Hypermelanotic macule
Hyperpigmented spots

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.
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.