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Disease Profile

Microcystic adnexal carcinoma

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



Rare Cancers


Microcystic adnexal carcinoma is a rare tumor of the skin that most often develops in the head and neck region, particularly in the middle of the face, though it may occur in the skin of other parts of the body as well.[1][2] The average age of diagnosis is 56.[3] This tumor is often first noticed as a bump or yellowish spot in the skin. Though microcystic adnexal carcinomas frequently grow into and disturb nearby tissues and is therefore considered an invasive cancer, this type of tumor rarely spreads to more distant parts of the body (metastasizes).[1] The main treatment for microcystic adnexal carcinoma is Mohs micrographic surgery, which is thought to improve the chances that all of the tumor cells are removed during surgery.[1][2][3]


Microcystic adnexal carcinoma appears as a smooth bump or patch that is slightly raised from the surrounding skin. It may be flesh-colored or yellowish, and it increases in size over time. A microcystic adnexal carcinoma may grow into nerves nearby, which can cause discomfort, numbness, tingling (paresthesia), burning, or itching.[1]


The underlying cause of this condition is not fully known. Risk factors appear to include radiation treatment, ultraviolet exposure, immunosuppression, and possibly genetics.[2][4][5]


Unfortunately, because microcystic adnexal carcinoma is a rare cancer, there is currently not enough information to determine if radiation therapy is an effective treatment for this disease. There are no guidelines for the use of radiation therapy as treatment for microcystic adnexal carcinoma, and little is known about the dose of radiation that might be needed to be effective.[6] Two articles studying a total of 17 patients receiving radiation therapy for microcystic adnexal carcinoma have suggested that there may be a benefit of radiation therapy for decreasing the chances of the tumor regrowing (recurrence),[6][7] and the authors suggest that this treatment could be considered if there is evidence that cancer cells remain after surgery, or in situations where additional surgery cannot be done.[7] However, another article raises concerns about the use of radiation therapy considering the small number of patients studied, the report of one patient's disease potentially worsening after radiation therapy, and the belief that exposure to radiation may be a risk factor for the initial development of this tumor.[1]

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

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • 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.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Microcystic adnexal carcinoma. Click on the link to view a sample search on this topic.


  1. Wetter R, Goldstein GD. Microcystic adnexal carcinoma: a diagnostic and therapeutic challenge. Dermatologic Therapy. 2008; 21:452-458. https://www.ncbi.nlm.nih.gov/pubmed/19076623.
  2. Lountzis NI. Microcystic Adnexal Carcinoma. Medscape Reference. September 24, 2014; https://emedicine.medscape.com/article/1101894-overview.
  3. Snow S, Madjar DD, Hardy S, Bentz M, Lucarelli MJ, Bechard R, Aughenbaugh W, McFadden T, Sharata H, Dudley C, Landeck A. Microcystic adnexal carcinoma: report of 13 cases and review of the literature. Dermatologic Surgery. 2001; 27:401-408. https://www.ncbi.nlm.nih.gov/pubmed/11298716.
  4. Abbate M, Zeitouni NC, Seyler M, Hicks W, Loree T, Cheney RT. Clinical course, risk factors, and treatment of microcystic adnexal carcinoma: a short series report. Dermatol Surg. 2003 Oct; 29(10):1035-8. https://www.ncbi.nlm.nih.gov/pubmed/12974700.
  5. Maloney ME. Microcystic adnexal carcinoma. UpToDate. February 5, 2016; https://www.uptodate.com/contents/microcystic-adnexal-carcinoma.
  6. Baxi S, Deb S, Weedon D, Baumann K, Poulsen M. Microcystic adnexal carcinoma of the skin: the role of adjuvant radiotherapy. Journal of Medical Imaging and Radiation Oncology. 2010; 54:477-482. https://www.ncbi.nlm.nih.gov/pubmed/20958947. Accessed 11/4/2011.
  7. Pugh TJ, Lee NY, Pacheco T, Raben D. Microcystic adnexal carcinoma of the face treated with radiation therapy: A case report and review of the literature. Head & Neck. 2011; March:Epub ahead of print. https://www.ncbi.nlm.nih.gov/pubmed/21384456. Accessed 11/4/2011.

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