Dermoscopy Basics

Abstract

This chapter highlights the fundamentals of dermoscopy. The “2 Step Algorithm” to distinguish between melanoncytic lesions and non-melanocytic lesions is outlined in a flow sheet. The flow sheet also provides a suggested management plan based on lesion appearance on dermoscopy. Descriptions and illustrations of benign lesions, suspicious lesions, and features concerning for cutaneous melanoma on the skin including special sites are provided in a chart format.

Dermoscopy: The 2 Step Algorithm [1,2,3] (Fig. 2.1)

The first part of the 2-Step Algorithm (Fig. 2.1) involves determining if a cutaneous lesion is a pigmented lesion or not (Table 2.1). A pigmented lesion typically presents with one or more pigment pattern(s) as described in Tables 2.2 and 2.3. The only exception to this rule is if the lesion is unequivocally a dermatofibroma. If the lesion contains at least one pigment pattern, then proceed to Step 2 for melanocytic lesions. If the cutaneous lesion does not contain at least one pigment pattern, then proceed to Step 2 for non-melanocytic lesions.

Figure 2.1

The 2-Step Algorithm

Step 1 (Table 2.1):

Table 2.1 Dermoscopic Findings of Common Cutaneous Lesions

Table 2.2 Dermoscopic Features of Benign Nevi

Table 2.3 Dermoscopic features of melanoma

Table 2.4 Melanoma of special sites