The reticular point of view in dermatoscopy

Different dermatoscopic algorithms have been developed to evaluate pigmented lesions of the skin, with pattern analysis being the most commonly used. We sought to develop and evaluate a diagnostic scoring system, the reticular point of view, to distinguish common melanocytic nevus from dysplastic nevus and from melanoma.

We analyzed 1543 pigmented lesions, most of which contained a pigment network, and assessed the presence of linear extensions, thickened or hyperpigmented lines, areas of abrupt cut off, and areas with large "holes." We then conducted statistical analyses on these parameters to verify which of these exerted the most influence on the dermatologist's decision to surgically excise the lesion and to verify which feature was most linked to histopathologic signs of dysplasia or malignancy.

Among the lesions excised, histopathologic examination revealed 33 (10.28%) melanomas. Among these, 25 (75.75%) showed an asymmetric distribution of the pigment network, whereas 20 (60.6%) showed a linear extension of it. The analysis of our data showed that all the evaluated criteria were statistically significant and played an important role in the dermatologist's decision to perform surgical excision of the lesion. Regarding the diagnosis of melanoma, only the presence of large holes, areas of abrupt cut off, and linear extensions revealed statistical significance.

Reticular point of view may be useful only in lesions with a large pigment network. It is not applicable in nodular, thick, and amelanotic melanomas that are usually lacking in pigment network.

Although pattern analysis represents the most effective analytical method in dermatoscopy, our scoring system may be useful to distinguish between benign lesions, which need only clinical follow-up, and malignant lesions, which need surgical excision.