Abstract
From the point of view of dermatoscopic examination, we consider the face, acral parts of the limb, nails and mucous membrane to be "atypical" locations. The anatomical structure of the skin differs in these areas, and therefore the dermatoscopic findings are also different.
On the face of elderly patients, we often diferentiate flat semorrheic keratosis (senile lentigo), pigmented actinic keratosis and lentigo maligna. From the point of view of dermatoscopy, this differential diagnosis is one of the most difficult in clinical practice.
Currrently, the so-called "inverse approach" is recommended, where we look for dermatoscopic criteria typical of seborrheic keratosis or actinic keraosis (Scales, white and enlarged follicles, erythema, brown lines in a parallel or reticular arangement, sharp lesion boundaries and structures common to seborrheic keratosis). In theis absence, we consider the manifestation to be risky with respect to lentigo maligna.
In unclear cases, we choose biopsy and histopathological examination.