Dermoscopy of melanoma

Some statistics have shown that when the dermoscopic exam is performed by a primary care physician, one melanoma in 30 surgical interventions is removed. The rate is lowered to one in 15 surgeries when the examination is carried out by a dermatologist using a dermatoscope.

A discrete number of ambiguous lesions can be considered baenign by dermoscopy and only a small fraction of these are removed to receive an histological biopsy.

Amelanotic melanoma

“Amelanotic melanoma” is a clinical term frequently used for any melanoma lacking melanin pigmentation. These tumors represent a large fraction of the so-called “featureless” or “undiagnosticable” melanoma.

Amelanotic melanoma cannot be identified by dermoscopy and can be easily mistaken with diabetic foot ulcers, warts, rhinophima, and eczema.

The face and the feet are the anatomical areas where the diagnosis of amelanotic melanoma is frequently missed.

Acral Lentiginous Melanoma

Acral lentiginous melanoma is an uncommon, cutaneous malignant tumour which may arise on the foot. It is relatively rare, and its atypical appearance and late presentation frequently determine its poor prognostic indicators.

Despite being the rarest form of cutaneous melanoma, acral lentiginous melanoma (ALM), is the most common type of lower limb extremities.

Its late presentation and the difficoulty usually found in its recognition contribute to its poor prognosis.

The name of this type of lesion derives from its usual occurrence on acral (distal) areas of the body, particularly the palms, soles and sub-ungual areas, and its distinct radial or 'lentiginous' growth.

ALM represents the rarest form of the four sub-types of cutaneous melanoma, yet is the most dangerous.