The ‘ABCDE” of melanoma is an acronym that has been developed to help clinicians and the public identify features in a skin lesion that may suggest an early or in situ melanoma.

‘A’ stands for Asymmetry 

‘B’ stands for Border irregularity 

‘C’ stands for Colour variability/Change

‘D’ stands for Different 

‘E’ stands for Evolving 

The ‘EFG’ of melanoma is another acronym that has been designed to help clinicians and the public identify skin changes in a lesion that may suggest a nodular melanoma.  In the given context, nodular refers to skin lesions that appear as bumps greater than 1 cm in diameter.

‘E’ stands for Elevated

‘F’ stands for Firm

‘G’ stands for Growing 

We will be looking at each acronym in greater detail.

‘A’ stands for Asymmetry: a melanocytic naevus is usually symmetrical, while melanoma usually appears in irregular or asymmetrical shape and/or colour.  

B’ stands for Border irregularity: a melanocytic naevus has even borders and is smooth, while melanoma has irregular, blurry, or pointed edges and a hard-to-define border. Moreover, during careful skin examination, the pigmented components of a healthy-looking melanocytic naevus fade out towards the edge, while edges of seborrheic keratosis or a solar lentigo are well defined. Similarly, the edges of melanoma have well-defined and fading segments.  

‘C’ stands for Colour variability/Change: a melanocytic naevus usually has a single shade of colour, two colours with one occurring inside the other, or regularly repeated (i.e.tan, brown, or pink). 

In the majority of cases, melanoma can be brown but it can have five or six colours, such as black, blue, tan, grey, pink, and red.  These colours are irregularly or unevenly distributed. 

‘D’ stands for Different: the majority of people have a “signature naevus”, which means that all their melanocytic nevi resemble each other. On the other hand, melanoma appears as a unique lesion that looks different from all other lesions.

A pigmented lesion that looks different from others is often called “odd-mole-out” and should be considered suspicious even if it does not necessarily fulfill the ABCDEFD criteria.

‘E’ stands for Evolving: a melanocytic naevus is usually stable and does not change with time in terms of size, colour, or shape. In a meantime, these changes may be noted over the course of several months-years in melanoma.

As previously mentioned, ‘E’ also stands for Elevated in the EFG acronym. Benign lesions like dermal naevus, cyst, or dermatofibroma can be elevated, but any new elevated or thickened lesion may be perceived as suspicious for nodular melanoma or another form of skin cancer.

‘‘F’ stands for Firm: Benign lesions like dermatofibroma may feel firm, but this feature is also common for nodular melanoma.

‘G’ stands for Growing: a nodular melanoma can grow rapidly with noticeable changes over a duration of several days to weeks. Meanwhile, benign skin lesions usually remain stable or change very slowly over years to decades. Their appearance may rapidly change in appearance over a few hours in cases of inflammation, injuries, or eczema.  

The ABCDEFG criteria are not inclusively used for melanoma as some of the criteria may be displayed by other types of skin cancer, like pigmented squamous cell carcinoma and basal cell carcinoma.

Melanocytic naevi can evolve in special circumstances like darkening after being exposed to the sun, during pregnancy, and age. For instance, lesions, such as solar lentigines and seborrheic keratoses routinely change over time.

The ABCDEFG criteria have been proven to be extremely helpful in identifying a potential melanoma. However, it is not efficient and reliable to recognize all melanomas. For instance, this criteria is not helpful in identifying less common subtypes of melanoma like melanoma in childhood and desmoplastic melanoma as they lack the features identified by ABCDEFG criteria. 

Melanoma is a very serious form of skin cancer that can progress quite quickly. It is treatable if identified at early stages. If the lesion is left untreated, it may spread to other body parts and be life-threatening.

If you have a skin lesion with ABCDE or EFG features that concern you, you have to see a dermatologist as soon as possible for assessment.

Centre for Medical and Surgical Dermatology offers various treatment options for melanoma which are unique for every patient. For more information about this condition, visit the following link: 

For more information about melanocytic naevus, visit the following link: