Segmental Nevus Depigmentosus: Analysis of 20 Patients

Abstract

Achromic nevus or nevus depigmentosus is a cutaneous abnormality consisting of a hypopigmented macular lesion which can present as circumscribed irregular, oval, or round or as a unilateral band or streak with a blocklike configuration or arranged along one or more Blaschko lines. When it is systematized, it is indistinguishable from hypomelanosis of Ito. Pigmentary anomalies along the lines of Blaschko can be associated with systemic features. For these reasons, 20 children, referred consecutively for evaluation of segmental, linear achromic nevus, were evaluated to define the incidence of associated abnormal systemic features. Extracutaneous abnormalities were present in 2 of 20 children (10%). The anomalies consisted of pes cavus ipsilateral to the hypopigmentation in one child and mental retardation, seizures, and hemihypertrophy in the second. This study confirms that achromic nevus, even when distributed along Blaschko lines, is commonly a benign lesion that is associated with systemic features in a small minority of cases.

Clinical and histopathologic characteristics of nevus depigmentosus

“…Three clinical patterns of ND are described: isolated, segmental, and whorled types. 2,7,[11][12][13] However, differentiating whorled ND from hypomelanosis of Ito is rather vague and there are controversies about differences between these two entities. 6,14 In contrast to ND, hypomelanosis of Ito shows a familial tendency and is usually associated with systemic abnormalities.…”

Hypomelanoses in children

“…According to some authors, there are three subtypes within the group of the nevi depigmentosi: an isolated form (solitary and well defined lesions), a segmental form (unilateral, band-shaped lesions, sometimes Blaschkoid distribution) and a systematized from (extensive whorls and streaks of hypopigmentation, following the lines of Blaschko [hypomelanosis of Ito or pigmentary mosaicism]). [19] The theory of Happle postulates that all linear hypo- and depigmented maculae following the lines of Blaschko are a consequence of mosaicism, even though a chromosomal mosaicism could not always be demonstrated. [20] Whenever this blaschkoid pattern is seen, neurological and musculo-skeletal abnormalities should be suspected.…”

Nevus depigmentosus treated with suction blister grafting: Follow-up after 10 years

“…The disease is primarily limited to the skin though there are reports of association[3] of neurological abnormalities and limb hypertrophy . The commonly used clinical diagnostic criteria for ND are as follows:[4]…”