Familial atypical multiple mole-melanoma syndrome in Adult
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Synopsis

Features associated with FAMMM syndrome include multiple cases of melanoma within a family, young age at diagnosis of melanoma, family members with pancreatic cancer, and family members with multiple primary melanomas.
The CDKN2A gene encodes two proteins, p16 and p14ARF, but mutations seen in melanoma families are associated more often with an impaired activity of p16. Not all mutation carriers will develop melanoma. Risk differences have been seen from one geographic area of residence to another, suggesting that sun exposure, or other co-inherited factors, also contribute to the incidence of the disease.
Melanoma in a patient with mutated CDKN2A occurs at a significantly earlier age (median 40 versus 50 years), and multiple primary melanomas are more common in individual patients (40% versus 15% in one study) compared with families harboring wild-type CDKN2A. The risk of pancreatic cancer is estimated to be 13-22 times higher for FAMMM syndrome patients than the general population. This risk increases to 38-fold in CDKN2A-mutant FAMMM syndrome patients. Nevi in patients with FAMMM syndrome are phenotypically diverse.
Melanoma-astrocytoma syndrome is a rare syndrome thought to be a variant of FAMMM syndrome secondary to loss of p14ARF function.
Related topic: amelanotic melanoma
Codes
ICD10CM:D23.9 – Other benign neoplasm of skin, unspecified
SNOMEDCT:
254819008 – Atypical mole syndrome
Look For
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Diagnostic Pearls
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Differential Diagnosis & Pitfalls
FAMMM syndrome is unique because the numbers of nevi in concert with a family history are needed for diagnosis. Other melanoma tumor syndromes include:- BAP1 tumor syndrome
- MITF tumor syndrome
- TERT/Shelterin mutations
Best Tests
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Management Pearls
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Therapy
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References
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Last Reviewed:08/15/2021
Last Updated:01/16/2022
Last Updated:01/16/2022


Overview
People with a lot of moles all over their body and a family history of skin cancer are said to have familial atypical multiple mole-melanoma syndrome (FAMMM syndrome), also known as familial atypical mole syndrome. A mole is a type of nevus. An atypical mole has an irregular shape, a varied color, and unclear borders.Those with atypical moles may be at increased risk for developing skin cancer (melanoma), with the risk increasing with the number of atypical moles present.
Who’s At Risk
People with familial atypical mole syndrome have a history of melanoma in their family (parents, siblings, grandparents, aunts, and uncles).Signs & Symptoms
- Atypical moles may appear anywhere on the skin.
- In familial atypical nevus syndrome, at least one mole will be larger than a pencil eraser (6 mm).
- Atypical moles have variations in color within one nevus, ranging from pink to reddish-brown to dark brown.
- People with familial atypical nevus syndrome may have hundreds of moles of varying sizes and colors.
Self-Care Guidelines
The best way to prevent skin cancer is to protect yourself from ultraviolet (UV) light:- Avoid exposing your skin to sunlight during peak sun hours (10 AM to 3 PM).
- Wear protective clothing.
- Use high-SPF sunscreen (SPF of 35 or greater).
When to Seek Medical Care
People with multiple moles should be examined by a dermatologist every 4-12 months depending on their past history and family history.Treatments
Your doctor may recommend that you have a biopsy or surgical removal (excision) of unusual-appearing moles to look for melanoma.Familial atypical nevus syndrome is often tracked with photographs. Your health care provider may want to keep a photographic record of your skin to detect changes.