The Usual Clinical Presentation of Suspicious Moles
Many patients present with pigmented lesions (moles) and the vast majority are not clinically suspicious moles. Experience in assessing suspicious moles is the most important factor in accurate diagnoses. Some of the available algorithms include: ABCD rule, Menzies method, 7-point rule, C.A.S.H., CHAOS and clues, BLINCK algorithm and the 3 point check list. My personal choice is the C.A.S.H. method described by Kopf et al. and is presented below.
Suspicious for melanoma
|Colours:Light brown, dark brown, black, red, white, blue
Score 1 point for each colour
|1-2 colours (1-2 points)||3-4 colours (3-4 points)||5-6 colours (5-6 points)|
|Architecture: Order vs disorder
Score 0-2 points
|None or mild disorder (no points)||Moderate disorder (1 point)||Marked disorder (2 points)|
|Symmetry:Consider contour, colours and structures
Score 0-2 points
|Symmetry in 2 axes (no points)||Symmetry in 1 axis (1 point)||No symmetry (2 points)|
|Homogeneity:Consider pigment network, dots & globules, blotches, regression, streaks, blue-white veil, polymorphous vessels
Score 1 point for each structure
|Only one structure (1 point)||2 types of structure (2 points)||3 or more structures (3-7 points)|
Add up the scores for a total C.A.S.H. score (2 to 17).
C.A.S.H. score of 7 or less is likely benign.
C.A.S.H. score of 8 or more is suspicious of melanoma.
When there is any doubt, we consider biopsy. I do not advocate or perform shave biopsies. Excision biopsy taking the full thickness of the dermis is the best. Incisional biopsies are only used for very large lesions and even then excision still warrants consideration.
An acceptable “hit-rate” for malignancy is 1 malignant biopsy in every 10. A higher “hit rate” should prompt the practitioner to excise more frequently. A lower “hit rate” should prompt the practitioner to consider a more thoughtful screening.
Generally speaking suspicious moles should be excised with only enough margin to ensure complete removal. 1-2 mm around the visible extent is usually. Definitive margins are then performed at another procedure as appropriate.
It is interesting to note that there is no adverse outcomes when the definitive surgery is performed within 3 weeks of the initial diagnostic procedure, which allows adequate time for complete pathological reporting, even if immunohistochemistry methods are required.