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| CASE REPORT |
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| Year : 2015 | Volume
: 2
| Issue : 2 | Page : 100-102 |
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Development of vitiligo within segmental nevus depigmentosus: A very rare presentation
KK Kamalakannan, P Arunprasath, Jasmin Susan Joy, V Sivasubramanian
Department of Dermatology and STD, Vinayaka Missions Medical College and Hospital, Karaikal, U.T. of Puducherry, India
| Date of Web Publication | 29-Dec-2015 |
Correspondence Address:
P Arunprasath
Department of Dermatology and STD, Vinayaka Missions Medical College and Hospital, Karaikal - 609 609, U.T. of Puducherry
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/2349-5847.172773
Nevus depigmentosus (ND) is a congenital leukoderma that is, stable in its size and distribution and may present as isolated, segmental or systematized form. Segmental ND sometimes can pose a diagnostic difficulty with segmental vitiligo. Likewise, segmental vitiligo overlaps with the clinical features of ND to a greater degree. A 15-year-old boy presented with two distinct asymptomatic pigmentary lesions involving the right thigh. Based on the clinical features, Wood's lamp examination and histological features a diagnosis of vitiligo arising within the confines of segmental ND was entertained. Though there are reports of vitiligo coexistent with ND in two different sites, and development of lentigines within ND, vitiligo developing within the preexisting ND makes this case an interesting presentation. Keywords: Nevus depigmentosus, segmental, vitiligo
How to cite this article:
Kamalakannan K K, Arunprasath P, Joy JS, Sivasubramanian V. Development of vitiligo within segmental nevus depigmentosus: A very rare presentation. Pigment Int 2015;2:100-2 |
| Introduction | |  |
Nevus depigmentosus (ND) is a congenital, nonprogressive, hypopigmented disorder whereas vitiligo is an acquired, and progressive depigmented disorder.[1] The presentation of segmental ND sometimes can pose a diagnostic difficulty with segmental vitiligo. Likewise, segmental vitiligo overlaps with the clinical features of ND to a greater degree. There are reports of ND coexistent with vitiligo, but at two different sites. A case of vitiligo developing within the confines of segmental ND is reported for its rare occurrence.
| Case Report | | |
A 15-year-old boy presented with two distinct asymptomatic pigmentary lesions involving the right thigh. A hypopigmented patch that was present since birth and multiple depigmented patches that developed within the preexisting hypopigmented patch by the age of 12 years. Family history was not contributory.
Dermatological examination revealed a hypopigmented patch starting from the lateral aspect of right thigh extending up to the anterolateral aspect of knee measuring approximately 30 cm × 15 cm, with irregular margins [Figure 1]. From the mid-thigh the patch crossed the anterior aspect to involve a medial aspect of thigh and knee [Figure 2]. Within which there were multiple depigmented patches, some with leukotrichia [Figure 3]. Near the depigmented patches in the upper thigh there were prominent atrophic striae probably topical steroid induced. Hair, nail, and mucous membranes were normal. The systemic examination did not reveal any abnormality. | Figure 1: Hypopigmented patch starting from the lateral aspect of right thigh extending up to anterolateral aspect of knee
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 | Figure 2: Hypopigmented patch crossing the anterior aspect in the mid-thigh to involve medial aspect of thigh and knee
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 | Figure 3: (a and b) Multiple depigmented patches within the confines of hypopigmented patch
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Baseline hematological and biochemical investigations were within normal limits. Wood's lamp examination of the hypopigmented lesion showed an off-white accentuation, whereas there was a chalky-white accentuation in the depigmented lesions. Histopathological examination (HPE) of the depigmented patch showed absence of pigmentation in the basal layer, so was the special staining with S-100 protein [Figure 4], while that of hypopigmented patch revealed pigmentation in the basal layer, and this result was confirmed with S-100 protein immunoperoxidase staining [Figure 5]. | Figure 4: Histopathology of the depigmented lesion showing absence of pigmentation in the basal layer (a) H and E, ×100 (b) S-100 protein immunoperoxidase staining, ×100
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 | Figure 5: Histopathology of the hypopigmented lesion showing uniform pigmentation in the basal layer (a) H and E, ×100 (b) S-100 protein immunoperoxidase staining, ×100
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Based on the clinical features, Wood's lamp examination and HPE a diagnosis of vitiligo arising within the confines of segmental ND was entertained. He was treated with topical tacrolimus and phototherapy for vitiligo and was reassured regarding the nonprogressive nature of ND.
| Discussion | | |
ND is a congenital, nonprogressive, hypopigmented lesion that is, stable in size and distribution.[2] ND occurs sporadically, and there is no known pattern of inheritance or familial tendency.[3] The pathogenesis is attributed to functional alteration of melanocytes, which interferes with the synthesis of normal melanosomes and their subsequent transport to neighboring keratinocytes without any reduction in the melanocyte count.[1]
Three subtypes of ND described includes an isolated form, a segmental form, and a systematized form.[2] Based on diameter, ND has been classified into Type I if it is < 10 cm and Type II if it is more than 10 cm. ND is further stratified into ND simplex, and complex depending on the absence or presence of associated abnormalities, respectively. Type II ND simplex should be differentiated from segmental vitiligo.[4] Similarly, segmental vitiligo which tends to show an earlier onset with a stable clinical course overlaps with the clinical features of ND to a greater degree.[5] In this way, ND and segmental vitiligo are mimickers of each other. However, the concurrent presence of both the conditions, in this case, is an uncommon presentation.
Vitiligo can be differentiated from ND in that it is an acquired, depigmented disorder showing abrupt onset, followed by progression for a time, then a period of stability and a characteristic chalky-white accentuation under Wood's lamp,[3] features similar to the present case.
HPE of ND shows normal to decreased number of melanocytes, and the results were reinforced with S-100 protein and other markers.[3] Histologically well-established lesions of vitiligo are totally devoid of melanocytes and immunohistochemistry studies using a panel of monoclonal antibodies including S-100 protein confirmed the same.[6] In the present case, HPE and special staining established the differential identities of ND and vitiligo.
Development of lentigines within ND had been reported to occur after narrow band ultraviolet B exposure, suggesting a possible activation of melanosome transfer, resulting in overproduction of melanin within ND.[7] Furthermore, Bolognia et al. and later Shim et al. had reported the occurrence of multiple lentigines and pigmented nevi, respectively, within the confines of segmental ND.[8],[9] These authors considered this change as a different form of repigmentation due to a reverse mutation in one of the genes involved in pigmentation.[8],[9] Whether the occurrence of vitiligo within the confines of segmental ND in the present case could possibly be attributed to reverse mutation is dubious.
| Conclusion | | |
To conclude, though there are case reports of vitiligo coexistent with ND in two different sites,[5],[10] and development of lentigines within ND, vitiligo arising within the confines of preexisting ND makes this case interesting and is a very rare presentation.
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Nil.
Conflicts of interest
There are no conflicts of interest.
| References | | |
| 1. | Lee HS, Chun YS, Hann SK. Nevus depigmentosus: Clinical features and histopathologic characteristics in 67 patients. J Am Acad Dermatol 1999;40:21-6.  |
| 2. | Deb S, Sarkar R, Samanta AB. A brief review of nevus depigmentosus. Pigment Int 2014;1:56-8.  |
| 3. | Kim SK, Kang HY, Lee ES, Kim YC. Clinical and histopathologic characteristics of nevus depigmentosus. J Am Acad Dermatol 2006;55:423-8. |
| 4. | Ruiz-Maldonado R. Hypomelanotic conditions of the newborn and infant. Dermatol Clin 2007;25:373-82, ix. |
| 5. | Hwang SW, Kang JH, Jung SY, Choi JH, Seo JK, Lee D, et al. Vitiligo coexistent with nevus depigmentosus: This was treated with narrow-band UVB and these lesions were followed using the Mexameter®, a pigment-measuring device. Ann Dermatol 2010;22:482-5. |
| 6. | Spielvogel RL, Kantor GR. Pigmentary disorders of the skin. In: Elder DE, Elenitsas R, Johnson BL Jr, Murphy GF, editors. Lever's Histopathology of the Skin. 9 th ed. Philadelphia: Lippincott Williams and Wilkins; 2005. p. 705-13. |
| 7. | Bardazzi F, Balestri R, Antonucci A, Spadola G. Lentigines within nevus depigmentosus: A rare collateral effect of UVB therapy? Pediatr Dermatol 2008;25:272-4. |
| 8. | Bolognia JL, Lazova R, Watsky K. The development of lentigines within segmental achromic nevi. J Am Acad Dermatol 1998;39(2 Pt 2):330-3. |
| 9. | Shim JH, Seo SJ, Song KY, Hong CK. Development of multiple pigmented nevi within segmental nevus depigmentosus. J Korean Med Sci 2002;17:133-6. |
| 10. | Kang IK, Hann SK. Vitiligo coexistent with nevus depigmentosus. J Dermatol 1996;23:187-90. |
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
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