18 October 2017

Guidelines for hard-to-detect melanomas

Cancer Clinical

Atypical melanomas can be dastardly difficult to detect. There is no typical pattern of atypia.

However, the Cancer Council Australia’s new guidelines, published in the MJA this month, at least provide some framework to help detect these tumours before they are advanced.

The guidelines acknowledge the early detection of superficial spreading melanomas has improved, with a reduction in both the median tumour thickness and the melanoma mortality.

However, the incidence of atypical melanomas only being diagnosed when they thicker lesions remains high in Australia, partly because they are so difficult to spot.

Atypical melanomas come in many guises. They often have peculiar or absent pigmentation, atypical vessels and symmetrical pigment patterns, and by definition do not follow the ABCD diagnostic criteria (asymmetry, border irregularity, colour variegation and a diameter of more than 6mm) of classic melanomas.

The main culprits include nodular melanoma, desmoplastic melanoma and acral lentiginous melanoma. Different subtypes can be mistaken for: scars; non-melanoma skin cancer; nail trauma or infection; and may mimic a plantar wart or macerated tinea infection.

Despite the differences, the guidelines state there is usually one shared characteristic gives away their identity. Melanomas change over time.

“Perhaps the most helpful clinical feature of biologically significant melanomas is that they are changing, regardless of their other clinical features,” the MJA article stated.

“Any lesion that is changing in morphology or growing over a period of more than one month should be excised or referred for prompt expert opinion.”

The guideline authors suggest adding EFG (elevated, firm and growing) criteria to the traditional ABCD criteria when assessing skin lesions. And importantly, they also stipulate urgent action if the lesion satisfies this criteria at the one-month mark.

MJA 2017; 9 October 

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Francis K F Tan
Francis K F Tan
1 year 4 days ago
I would like to add that a recommendation to our patients in relation to self skin examination should include the following: answer these questions if you have a concern about a skin lesion 1) am I looking at a lesion which could be new? – yes; take note of its size, shape, colour ; check it again after 2-3-4 weeks for any change(s); if change(s) have been noted, see your GP or your skin cancer doctor 2) am I looking at a lesion which is well known to me? – yes; has it changed in its size, shape, colour within… Read more »