Tips and tricks in the dermoscopy of pigmented lesions

Abstract

Dermoscopy is a useful, widely used tool for examining pigmented lesions, especially helpful in cases of an uncertain nature. Nevertheless, doctors may experience diagnostic difficulties while using this method. An example of this may be found in the examination of subcorneal hematoma, dark nevi with black lamella or lesions of acral volar skin. In such cases, a few diagnostic tricks have proven to be helpful in achieving diagnostic accuracy. This paper reviews various methods of performing dermoscopy, suggesting a number of simple, yet helpful tests. These include the adhesive tape test, the skin scraping test and the ink furrow test. The adhesive tape test is helpful in differentiating between dark melanocytic nevi and melanoma. Hematoma may be more easily differentiated with the use of the so-called skin scraping test. The confirmation of benign and melanocytic lesions of acral volar skin, on the other hand, is more accurate when using the ink furrow test. These methods have been discussed here based upon a series of literature reviews, the authors' own experience and, also, iconography. The present article describes novel methods used in dermoscopy, helping to bring about a faster, more accurate diagnostics of those lesions which have proven to be more difficult to recognize. Helpful tricks, such as have been known to professional literature, as well as the authors' own experience (for instance, applying urea cream to hyperkeratotic lesions or using photographs of skin lesions taken with the aid of a mobile phone camera--all prior to surgery) will surely be considered beneficial to the practitioner, be it dermatologist or any other physician.

Figure 1

ab. Dermoscopic image of melanocytic nevus in non-polarized light source without immersion (Figure 1a) compared to non-polarized light source with immersion (Figure 1b).

Figure 2

abc. A profile of melanocytic nevi: right thigh, woman, age 30, skin phototype I, red hair. Dermoscopy reveals light-brown colour with shades of pink, central hypopigmentation and numerous dotted-type vessels.

Figure 3

a. Dermoscopic image of melanocytic nevus prior to adhesive tape test. b. Dermoscopic image of melanocytic nevus following adhesive tape test (pigment network is more visible, black lamella has been torn off).

Figure 4

Dermoscopic image of acral melanocytic nevus with typical parallel furrow pattern.

Figure 5

Ink furrow test: the ink settles in the sulcus, which correlates with the dispersion of the dye in a mild case of melanoma.

Figure 6

Dermoscopic image of subcorneal hematoma of the feet shows typical parallel ridge pattern.

Figure 7

a. Macroscopic image of subcorneal hematoma. b. Dermoscopic image of hematoma after scraping test- homogenous brownish masses are visible.

Figure 8

Marking of suspected lesions before surgical removing. The patient can easily point the suspected skin lesions after performed dermoscopy, especially in the atypical mole syndrome - while above 300 lesions can exist on whole the body.