III.3.1 Definition
An agminated nevus consists of multiple pig- mented lesions of the same kind, occurring in a cluster or circumscribed group in a localized area of the body.
III.3.2 Clinical Features
Agminated nevi are infrequent lesions. Clini- cally they appear as numerous brown to red macules or papules in different sizes and in a peppered distribution over a certain area of the skin. Pigmented lesions that have been described in the literature as agminated include blue nevi [1], Spitz nevi [2], congenital melanocytic nevi [3], common acquired melanocytic nevi, multi- ple lentigines [3], and lesions within nevi spili [5]. In most cases, agminated nevi develop in puberty.
Chapter III.3
Agminated Nevus
Ulrike Weigert and Wilhelm Stolz III.3
Contents
III.3.1 Definition . . . .75
III.3.2 Clinical Features . . . .75
III.3.3 Dermoscopic Criteria . . . .75
III.3.4 Relevant Clinical Differential Diagnoses . . . .75
III.3.5 Histopathology . . . .75
III.3.6 Management . . . .75
References . . . .77
III.3.3 Dermoscopic Criteria
Each pigmented lesion within the cluster has to be examined individually. They are usually symmetrical and uniformly pigmented. If the pigment is in the upper dermis, they may have a blue-gray color.
III.3.4 Relevant Clinical Differential Diagnoses
A possible differential diagnosis is nevus spilus lacking clinically visible background pigmenta- tion. It commonly appears during late infancy or early childhood. A tan lentiginous back- ground patch on which more darkly pigmented macules and papules are distributed character- izes the lesion. Wood’s light examination or UV photography may be helpful to detect the back- ground pigmentation.
III.3.5 Histopathology
Dependent on the underlying type of nevus, regularly shaped pigmented or non-pigmented nevus cell nests can be seen at the dermo-epi- dermal junction or in the dermis.
III.3.6 Management
Usually no therapy is needed. If a given lesion
appears dermatoscopically irregular, excision is
recommended.
76 U. Weigert, W. Stolz
III.3
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