|THROUGH THE DERMOSCOPE
|Year : 2017 | Volume
| Issue : 2 | Page : 121-123
Dermoscopy of Nevus Depigmentosus
Balachandra S Ankad1, Swapnil Shah2
1 Department of Dermatology, S. Nijalingappa Medical College, Bagalkot, Karnataka, India
2 Skin and Laser Clinic, Solapur, Maharashtra, India
|Date of Web Publication||1-Dec-2017|
Balachandra S Ankad
Department of Dermatology, S. Nijalingappa Medical College, Near APMC, Navanagar, Bagalkot 587103, Karnataka
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Ankad BS, Shah S. Dermoscopy of Nevus Depigmentosus. Pigment Int 2017;4:121-3
A 30-year-old female presented with depigmented patch on the right elbow since birth. The lesion was slowly growing as she grew and attained the present size. Examination revealed a well-defined depigmented patch measuring about 4 × 2 cm with well-defined, irregular, and serrated borders. Few black hairs were seen emerging from the lesion [Figure 1]. There was no change in the color, size, and texture of the lesion from 10 years. On the basis of the history and clinical findings, a provisional diagnosis of nevus depigmentosus (ND) was made and confirmed by histopathology with special stains. Videodermoscopy (FotoFinder, polarized, 20×) revealed whitish structureless areas covering the entire lesion with pseudopods at periphery. Subtle pigment network was noted on the background of white areas. Perifollicular pigmentation was also noted [[Figure 2] and [Figure 3]]. ND is an uncommon congenital pigmentary disorder characterized by the circumscribed area of depigmentation. It may appear at birth or continue to appear through adulthood. It increases in size with the growth of the body attaining its maximum size and remains the same size throughout life. Usually, the diagnosis of ND is straightforward on the basis of history and clinical manifestation. Close differentials are vitiligo, nevus anemicus, and ash leaf macules. Clinical features may not suffice to derive a diagnosis of ND mandating histopathology with special staining methods. Dermoscopy can be utilized in such scenario and it demonstrates white areas with faint pigment network over the entire lesion with the perilesional pigment network of normal skin. White dots corresponding to eccrine duct openings and pseudopods suggesting serrated borders are described. In the present case, perifollicular pigmentation and subtle reticular pigment network in the background of diffuse whitish structureless area were noted. Serrated borders extending onto the normal skin appeared as “pseudopods.” The areas of total loss of pigment were conspicuously absent in ND. The presence of pigment in the ND lesions reinforces the fact that melanocytes are present in the lesions of ND; only their transfer to the keratinocytes is defective.
|Figure 1: Clinical image showing well-defined, depigmented patch on the right elbow|
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|Figure 2: Dermoscopy shows faint reticular pigment network (stars), serrated borders (pseudopods) (circle), and perifollicular pigmentation (arrow)|
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|Figure 3: Dermoscopy demonstrates subtle reticular pigment network (stars), serrated borders (pseudopods) (circles), and prominent perifollicular pigmentation (arrows)|
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The dermoscopy of vitiligo shows white areas. Absence of pigment network, reverse pigment network; perifollicular and perilesional pigmentation are the other patterns described in vitiligo [[Figure 4]a and [Figure 4]b]. However, pseudopods are not seen in vitiligo. In ash leaf macules, the zones of white areas with the total loss of pigmentary network and faint reticular network are described [[Figure 4]c and [Figure 4]d].
|Figure 4: Clinical images of vitiligo and ash leaf macule (a and c) and dermoscopy of vitiligo show absent pigment network and diffuse white areas (b), whereas the dermoscopy of ash leaf macule demonstrates the zones of absence (black stars) and presence (red stars) of pigment network (d)|
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White colored lesions are considered social stigma, especially in the Indian subcontinent. Patients with depigmented patches come to dermatologists thinking that the lesions might be vitiligo. Therefore, it is mandatory to make accurate diagnosis and to rule out vitiligo. Dermoscopy demonstrates the characteristic patterns in ND, vitiligo, and ash leaf macules.
In conclusion, dermoscopy is a useful tool to evaluate the pigment distribution and structure in pigmentary conditions. It is a rapid and non-invasive method and is an adjunct to diagnostic techniques in ND apart from the existing ones such as Wood’s lamp examination and diascopy. In the present case, dermoscopy was useful in the diagnosis of ND, demonstrating the presence of pigment network. Nevertheless, the dermoscopic patterns observed here are based on single-case scenario. The authors recommend further studies involving large sample size to establish the usefulness of dermoscopy in ND.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]