Dermatology Online Journal

Midline eccrine nevus
Michael S Borkin MD, Henry J Votava MD, Nanette B Silverberg MD
Dermatology Online Journal 17 (12): 4

Department of Dermatology, St. Luke's-Roosevelt Hospital Center and Beth Israel Medical Center, New York, New York

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Abstract

Eccrine nevus is a rare benign solitary lesion with increased size and number of eccrine coils, ductal wall thickening, and luminal dilation, in the absence of collagen or fibroblast overgrowth. We present a 3-month-old male with a mid-line nuchal scalp lesion shaped like Mickey Mouse's head since birth that yielded a biopsy proven diagnosis of an eccrine nevus.

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Case report

A 3-month-old male, born full-term by normal vaginal delivery without complications, presented for a mid-line nuchal scalp lesion, which had been noted at birth. The parents reported that the lesion was growing with the child, did not change in color or with crying, and did not pulsate. Family history was non-contributory and the child was developmentally normal for age.

Upon examination, the child had a three-lobed tumor of rugose and fleshy skin located on the nuchal scalp and not in proximity of the posterior fontanelle. The central component was 1 cm by 2 cm and the “ears” were each 6 mm. The shape of the lesions gave the appearance of Mickey Mouse’s head with 2 ears. The lesion also had prominent whirling of the hair surrounding and central alopecia (Figure 1). An MRI was performed which demonstrated normal brain architecture and vasculature and no intracranial communication with the overlying lesion.

Figure 1	Figure 2
Figure 1. A three-lobed tumor of rugose and fleshy skin located on the nuchal scalp. The nodule also had prominent whirling of the hair surrounding a central alopecia. Figure 2. Increased number of enlarged eccrine coils in the reticular dermis with mild thickening of the ductal walls and dilatation of lumina in the absence of overgrowth of any other type of cutaneous cell or adnexae, consistent with an eccrine nevus. (H&E, x4)

A biopsy was then performed with histopathology demonstrating an increased number of enlarged eccrine coils in the reticular dermis, mild thickening of the ductal walls, and dilatation of lumina in the absence of overgrowth of any other type of cutaneous cell or adnexae consistent with an eccrine nevus (Figure 2).

Discussion

An eccrine nevus is a rare benign solitary growth with increased size and number of eccrine coils, ductal wall thickening, and luminal dilation in the absence of collagen or fibroblast overgrowth [1]. When associated with extra small vascular channels, the lesion is termed eccrine angiomatous hamartoma. If additional peri-glandular mucinous deposits are present, it is termed a mucinous eccrine nevus [2, 3].

Eccrine nevus is usually present at birth or develops by early childhood [2, 3]. Fewer than 20 cases have been reported with an equal sex distribution [2, 3, 4]. Lesions can be asymptomatic or hyperhidrotic and may appear as flesh colored to brown papules with or without central depression or surrounded by a scaly border [2, 3]. Lesions commonly occur on the extremities [2, 3, 4]. If multiple lesions exist, they may take on a linear distribution [2].

For symptomatic eccrine nevi, treatment may include topical aluminum chloride, with or without a systemic anticholinergic medication [3]. Newer reports show efficacious treatment with botulinum toxin injections to help reduce the hyperhidrosis [3]. Excision can remove well demarcated lesions [3].

Our case is unique in that it occurred on the midline scalp, causing a suspicion of underlying anomaly. A case of systematized organoid epidermal nevus with eccrine differentiation associated with blepharophimosis, mental retardation, multiple facial and oral pox-like lesions, gingival synechiae, and body asymmetry has been reported. In that case, the lesions followed the Lines of Blaschko, as opposed to our patient’s focal, oval tumor [5].

Another unique variant of an eccrine nevus, a coccygeal polypoid eccrine nevus (CPEN), has been reported [4]. CPENs are present at birth, and asymptomatic. Polypoid forms that can resemble skin tags may emerge in the coccygeal region without underlying spinal defects [4].

References

1. Elder DE, Elenitsas R, Johnson BL, Murphy GF, Xu X. Lever’s Histopathology of the Skin. 10th Edition. 2009;Chapter 30:883.

2. Llombart B, Molina I, Monteagudo C, Ramon D, Martin JM, Sanchez R, Jorda E. Mucinous eccrine nevus: an unusual lesion in a child. Pediatric Dermatology. 2003;20(2):137-139. [PubMed]

3. Hania S, Shwayder T. Eccrine nevus presenting as a hypopigmented patch. Pediatric Dermatology. 2008;25(6):613-615. [PubMed]

4. Park MY, Lee ES. Two cases of coccygeal polypoid eccrine nevi presenting as skin tags. Ann Dermatol. 2009;21(4):440-442. [PubMed]

5. Castori M, Annessi G, Castiglia D, et al. Systematized organoid epidermal nevus with eccrine differentiation, multiple facial and oral congenital scars, gingival synechiae, and blepharophimosis: a novel epidermal nevus syndrome. Am J Med Genet A. 2010;152A(1):25-31. [PubMed]

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