Melanomas

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When to suspect malignant change in a mole? Look for the following 5 changes (ABCDE):

Asymmetric shape

Border is irregular or blurred

Color is not uniform

Diameter greater than 6 mm

Evolving changes from past appearance

Various types of melanoma are described as follows:

Superficial spreading:

It is most common on the trunk and on the legs and commonly seen in 30-50 year olds. It typically is a flat or barely elevated brownish lesion with inhomogeneous color. Histology reveals buckshot scatter of malignant melanocytes.

Nodular:

Also seen commonly on legs and trunk. Starts as a dark papule which may become a nodule and ulcerate. It can lack the pigment sometimes and appear skin colored (amelanotic nodular melanoma). It is often well rounded and homogeneously pigmented leading to delay in diagnosis. This is the only relatively common melanoma that does not show a radial growth phase.

Lentigo maligna:

Commonly seen on head, face, neck, shoulders and arms in elderly light skinned individuals. It has extremely slow growth and it can exist in the in-situ form for years before growing.

Acral lentiginouS:

This is relatively less common in whites but accounts for upto 2/3rds of melanoma cases in dark skinned populations. The diagnosis is often delayed and hence prognosis is relatively poor. As the name suggests it occurs on hands and soles. It can also occur in the nail bed.

Amelanotic:

These are uncommon and appear as flesh-colored lesions often confused with carcinomas. As mentioned above it most commonly occurs in nodular form.

Treatment for melanoma is primarily surgical although trials of Interferon alpha have been successful to some extent. The most important predictor of prognosis is the thickness at the time of diagnosis (Breslow Index).

Posted in: MEDICAL,USMLE