The occurrence of melanoma has been on the rise in
the United States throughout the last few decades.
From 7.5 per 100,000 people affected in 1973, it increased
to 22.6 per 100,000 in 2001 among the white populations,
a group most prone to this disorder. The mortality
rate associated with the occurrence of melanoma is
also on the rise, which makes the accurate detection
of melanoma at the earliest possible time period extremely
vital for improving public health.
In 1985 the ABCD criteria was established as a simple
tool for alerting lay persons and primary health care
doctors and to help them diagnose the early incidence
of potentially curable melanoma. It consists of a
series of simple parameters that can be employed in
daily life as a simple mnemonic to make people, as
well as doctors, aware of the clinical features of
The ABCD Criteria
In the mnemonic ABCD; A stands for asymmetry, B stands
for border irregularity, C for color variegation and
D for diameter greater than 6mm. Asymmetry, border
irregularity, and color variegation are all associated
with melanoma lesions whose diameter are more than
6 mm. This finding led to the framing of the ABCD
criteria. Now these well known parameters are used
by clinicians worldwide for determining melanoma malignancy
and help to evaluate pigmented cutaneous lesions that
may need a specialist’s attention. If required,
the character of the pigmented lesions identified
through the ABCD criteria are to be ascertained through
advanced dermoscopy or biopsy or a combination of
both methods for more accurate diagnosis.
Ulcerated lesions are not included in the evaluation
as only characteristics of early melanomas are to
be explained by means of ABCD. As ulcerated pigmented
lesions that look suspicious would have been obviously
considered for excision and pathology regardless of
other parameters it is unnecessary to include these.
Thus, ABCD is an aid to identify a sub group of melanoma,
which are early thin tumors and are likely to be mistaken
for benign pigmented lesions and left untreated. These
criteria were defined to help non-dermatologists in
distinguishing normal moles from cancerous melanomas.
Many critics of the ABCD criteria stress that atypical
nevi and sebhorreic keratoses have properties similar
to those included in the ABCD parameters of melanoma.
However, the evidence of reliable sensitivity and
specificity with sufficient inter-observer agreement
in the application of melanoma established that this
is indeed a vital screening tool to be used in clinical
assessment. Not all melanomas have all ABCD characteristics
but a combination of features makes cutaneous lesions
most suspicious for melanoma.
Latest Addition to the ABCD Criteria
Over the later years this ABCD mnemonic as a screening
tool for incidences of cutaneous lesions has been
controversially debated, verified, and described in
order to establish its utility. The parameter D, which
stands for diameter of lesions more than 6 mm was
reviewed but has not been changed for the time being.
Small diameter melanomas are those which are 6 mm
or less in diameter. It has been found that small
diameter melanomas constituted less than 5% of all
invasive melanomas. Thus, it is considered unwise
to lower the diameter criteria of the ABCD parameters
to increase the sensitivity of melanoma without compromising
specificity leading to unnecessary excision. It should
be borne in mind that ABCD tool has the greatest capability
used in combination while analyzing small lesions.
More importantly, the addition of the parameter E,
which recognizes evolving lesions (i.e. lesions that
change over time), has been considered and accepted.
Thus, the mnemonic now reads ABCDE. The parameter
E has been included to emphasize the importance of
evolving pigmented lesions in the natural process
of melanoma progression. E, denoting “evolving”,
explains the dynamic character of this skin malignancy,
especially for the diagnosis of nodular melanomas,
which greatly contribute to melanoma related deaths.
These kinds of melanoma lack asymmetry, border irregularity,
color variegation and diameter greater than 6 mm.
Lesion change is noticed in 78% of nodular melanomas.
Evolving lesions are defined as those which change
in respect to size, shape and symptoms, surface or
shades of color. E for Evolving is a more accurate
term than the also suggested E for “enlargement” as
the latter focuses only on the size and excludes other
important feature changes vital for development of
melanomas. The role of lesion evolution as a primary
characteristic of cutaneous melanoma and resulting
in biopsy in diagnosed melanomas is well established.
Changes in size, elevation and color taken together
is the most probable pointer to melanoma malignancy,
other symptoms being bleeding, itching, tenderness
and ulceration. Lesions that are enlarged and non-uniform
are four times more likely to be melanomas than those
which did not meet these criteria.
Organizations like the American Cancer Society and
the Skin Cancer Foundation have acknowledged lesion
change to be a significant parameter in early diagnosis.
Thus, ABCDE is a comprehensive, clear and simple tool
to educate the public and physicians alike about the
salient features of melanoma. Since early and accurate
management of pigmented cutaneous lesions will help
physicians to decide whether surgical procedure is
necessary to remove such deadly cancers which can
be still curable.