What Is the Mole Alphabet Again?

Patient Presentation
An 8-year-old female came to clinic for her health supervision visit. She and her parents had no concerns about her health or development. The past medical history was non-contributory. The family history was positive for light-skinned individuals with many freckles but no other dermatological problems.

The pertinent physical exam showed a happy female with normal vital signs and growth parameters in the 75-90%. Her physical examination was normal except for many freckles scattered across her nose and cheeks, on her light complected skin. She had one nevus on her upper shoulder that was 4 mm, flat, uniformly medium brown with symmetric borders and no halo of surrounding skin. The diagnosis of a healthy female was made. When the nevus was noted the mother said that it showed up recently. She felt that it didn’t look bad to her and she felt it had not changed in any way. The pediatrician agreed with her assessment and reviewed the ABCDE’s of skin lesions and recommended that especially because of her light complected skin that she use sunscreen daily.


Melanocytic nevi or moles are pigmented nevi that are extremely common in children with ~ 98% of Caucasian children having at least 1 by early childhood. They are caused by benign melanocyte growth. These nevi reside in the epidermis or dermis, whereas regular melanocytes that produce general skin pigmentation reside in the basal layer. Moles are very often uniform – they basically look the same within the individual. The number of moles increases in the first 2-3 decades of life. Teens having 15-25 moles. They can also disappear.

Congenital melanocytic nevi are found in 1-3% of newborns and grow in proportion to the size of the child. They are graded based on the predicted adult size. Estimated lesion size increase from infancy to adult is 1.7x for the head, 3.3 on the legs and 2.8 on all other body areas. Small (< 1.5 cm) and medium size ( 40 cm) have a 5% lifetime risk. Congenital melanocytic nevi also can change over time. “They may begin as flat, evenly pigmented patches or thin plaques and later become more elevated with lighter, darker, or mottled pigmentation and a mammillated, rugose, verrucous, or cerebriform surface.” They can also develop superimposed papules or nodules which may be concerning for melanoma and need evaluation.

Acquired melanocytic nevi start to appear after 6 months of age. Changing of acquired moles is common. “Most new nevi [are] small and flat, and there [is] a general tendency for existing flat nevi to either become elevated or disappear.” In children they tend to become softer also. Location by itself is not necessarily a problem, but sites such as the head, back or genital area can be more difficult to monitor for the patients and families. Spitz nevus is an acquired, benign melanocytic neoplasm that occurs in children. It often is a single papule on the face or lower extremity that is brown, tan, black, pink or red. On dermatoscopy it appears to have a characteristic sunburst pattern. They are benign but can have histopathological features that overlap with melanoma and therefore a dermatologist usually manages this problem.

Melanoma is always a concern with moles that are not uniform in some way. Melanoma is very rare in children before puberty and uncommon in teens. For those < 10 years of age the lifetime risk is ~ 0.05%, and for patients 10-20 years the lifetime risk is ~0.5%. If there is a concern for possible melanoma, then a dermatologist should be consulted for help with initial evaluation and potentially for ongoing monitoring.

Learning Point
The alphabetical mnemonic for possible melanoma when assessing moles is:

A – Asymmetry – when the lesion is bisected, one half of the individual lesion looks different from the other half in size, shape, texture or color.
B – Borders – a mole should have uniformly well-demarcated or crisp edges. Borders that are irregular or ill-defined are suspicious.
C – Color – a mole should have uniform color. Multiple colors or blue, black, white or red areas are cause for concern.
D – Diameter – while moles can be any size, those that are > 6 mm (size of a pencil eraser) are more concerning.
E – Evolution – A mole that is changing in size, shape, texture or color is concerning. Normal moles in children can become softer and elevated slowly over time. If changing quickly or different from the evolution of other moles in an individual patient, this is concerning.
New symptoms such as itching, bleeding or crusting is also a reason for concern.

“Ugly duckling” is the term used for a mole that is very different than other moles in the same patient. An ugly duckling is also a concern. “Melanomas in children tend to be amelanotic and nodular, presenting as a rapidly growing “bump” that may mimic a pyogenic granuloma, keloid or wart rather than a changing nevus.”

Questions for Further Discussion
1. How do you monitor nevi in your practice?
2. What type of sunscreen do you recommend to use and at what age do you recommend starting to use it?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Moles and Melanoma.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Schaffer JV. Pigmented lesions in children: when to worry. Curr Opin Pediatr. 2007 Aug;19(4):430-40.

Schaffer JV. Update on melanocytic nevi in children. Clin Dermatol. 2015 May-Jun;33(3):368-86.

Mann JA. Update on pediatric dermatologic surgery from tots to teens. Curr Opin Pediatr. 2014 Aug;26(4):452-9.

Society for Pediatric Dermatology. Patient Perspectives: Moles and melanoma in children and teens. Pediatr Dermatol. 2015 Nov-Dec;32(6):e320-1.

Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital