Dermatology: Practical and Conceptual


126 Observation  |  Dermatol Pract Concept 2018;8(2)11

DERMATOLOGY PRACTICAL & CONCEPTUAL
www.derm101.com

Case Presentation

A 32-year-old woman with multiple Clark’s nevi, a negative 

family history for melanoma, and skin phototype III presented 

for the first time in October 2016 for a routine mole assess-

ment. An asymmetric, asymptomatic flat, 20 x 8 mm large 

pigmented lesion on her back was noted. Upon dermoscopy 

an atypical pigmented network with eccentric pigmentation 

and a small blue veil area were present (Figure 1).

The patient could not report a precise medical history. 

At a 6-month digital dermoscopic follow-up, the lesion 

was not enlarged but had changed and presented a more 

pronounced atypical network with accentuation of the blue 

Dermoscopy of a Spark’s nevus
Giovanni Biondo1,2, Matteo Gnone3, Simona Sola4, Carlotta Pastorino2, Cesare Massone2

1 Dermatology and Sexual Transmitted Disease Unit, “P. Giaccone” Hospital, University of Palermo, Italy

2 Dermatology Unit, Galliera Hospital, Genoa, Italy

3 Dermatology Private Practice, Genoa, Italy

4 Surgical Pathology, Galliera Hospital, Genoa, Italy

Key words: Spark’s nevus, dermoscopy, pathology

Citation: Biondo G, Gnone M, Sola S, Pastorino C, Massone C. Dermoscopy of a Spark’s nevus. Dermatol Pract Concept. 2018;8(2):126-
128. DOI: https://doi.org/10.5826/dpc.0802a11

Received: October 13, 2017; Accepted: December 7, 2017; Published: April 30, 2018

Copyright: ©2018 Biondo et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, 
which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Funding: None.

Competing interests: The authors have no conflicts of interest to disclose.

All authors have contributed significantly to this publication.

Corresponding author: Cesare Massone, MD, Dermatology Unit, Ospedali Galliera. Via Volta 6, 16128, Genova, Italy. Tel. ++ 0039 010 
5632 4270; Fax. ++0039 010 5632 4272. Email: cesare.massone@galliera.it

Spark’s nevus is a particular type of melanocytic nevus that on histology shows features of both Spitz’s 
and Clark’s nevus. Clinically, it is an asymmetric, irregular, multicolored, pigmented lesion that is not 
clearly distinguishable from melanoma or dysplastic (Clark’s) nevus. Dermoscopic features have not 
been described yet, and one could speculate that they are similar to those of Clark’s nevi because the 
histopathologic architecture of Spark’s nevus is similar to that of a Clark’s nevus, resembling Spitz’s 
nevi in the epithelioid morphology of melanocytes. We present a 32-year-old woman with a Spark’s 
nevus, who upon dermoscopy showed a pronounced atypical network with accentuation of the blue 
veil and mostly peripheral dots.

ABSTRACT

Figure 1. Dermoscopy at baseline: atypical pigmented network with 

eccentric pigmentation and a small blue veil area are present. [Copy-

right: ©2018 Biondo et al.]



Observation  |  Dermatol Pract Concept 2018;8(2):11 127

pigmented lesion, not clearly distinguishable from melanoma 

or dysplastic (Clark’s) nevus.

The first description has been attributed “verbally” to 

Ackermann, but the eponym and morphological descrip-

tion of Spark’s nevus (Spitz’s and Clark’s) was coined by 

Glusac in 2009 [1]. In 1991, Barnhill et al reported a series 

of  95  pigmented melanocytic spindle cell nevi (PSCN), 

8 of which exhibited some overlap with dysplastic nevus 

called pigmented spindle cell nevus (PSCN) with dys-

plastic changes [2]. Toussaint and Kamino found 67 out 

of 2,164 dysplastic nevi showing features of Spitz’s nevus 

[3]. Spark’s nevus was reported more frequently on the 

trunk and lower extremities and in women with a mean 

age of 33 [1]. According to Glusac, histological features 

of Spark’s nevus are: small size (<1 cm), flat/horizontal 

orientation, symmetric outline, uniform spitzoid cytology 

across the entire lesion, nest of similar size and shape when 

not bridged, and sharp circumscription [1].

The differential diagnosis includes Clark’s (atypical, 

dysplastic) nevus, Spitz’s nevus, and melanoma. Clark’s nevi 

are melanocytic nevi characterized clinically by variable size, 

borders, and colors that are difficult to distinguish from mela-

noma [4–6]. Upon dermoscopy Clark’s nevi show a variety 

veil and most peripheral dots had appeared. Because the 

modifications were recorded at digital follow-up, the lesion 

was excised (Figure 2).

Histopathology showed a junctional and dermal mela-

nocytic proliferation composed of nests predominating 

over single melanocytes, absence of pagetoid spread in the 

epidermis, and elongation of the rete ridges with lamellar 

fibrosis in the papillary dermis together with melanophages 

and inflammatory infiltrates (Figure 3). The nests were 

regular. In the epidermis, they were exclusively located at the 

dermoepidermal junction, and there were monomorphous 

round-to-oval epithelioid pigmented melanocytes reminis-

cent of Spitz nevus (Figure 4). As a whole, on histopathology 

this lesion showed the architecture of a Clark’s nevus, but 

the morphology of melanocytes are more typical of Spitz’s 

nevus and the features are characteristic of a Spark’s nevus, 

compound type.

Conclusions

Spark’s nevus is a particular type of melanocytic nevus with 

histology that shows features of both Spitz’s and Clark’s 

nevus. Clinically, it is an asymmetric, irregular, multicolored, 

Figure 2. Dermoscopy at 6-month follow-up. The lesion was not en-

larged but changed, presenting a more pronounced atypical network 

with accentuation of the blue veil and peripheral dots appeared. 

[Copyright: ©2018 Biondo et al.]

Figure 3. Junctional and dermal melanocytic proliferation composed of nests predominating over single melanocytes, absence of pagetoid 

spread in the epidermis, and elongation of the rete ridges with lamellar fibrosis in the papillary dermis together with melanophages and in-

flammatory infiltrates (hematoxylin and eosin [H&E], 40x). [Copyright: ©2018 Biondo et al.]

Figure 4. The nests are regular, exclusively located at the dermoepi-

dermal junction and present monomorphous round-to-oval epithe-

lioid, pigmented melanocytes reminiscent of those of Spitz’s nevus 

(H&E, 200x). [Copyright: ©2018 Biondo et al.]



128 Observation  |  Dermatol Pract Concept 2018;8(2)11

globules that are typical features of pigmented Spit’s nevi on 

dermoscopy, but it showed a prominent pigmented network, 

a blue veil, and dots.

The collection and examination of a large series of cases is 

needed to define prevalent clinical and dermoscopic features 

of Spark’s nevus.

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of reticular, globular and structureless patterns or mixed pat-

terns with different areas of hyper- and hypopigmentation. 

Histologically Clark’s nevus exhibits an increased number 

of single melanocytes and nests along the basal layer with 

elongation of rete ridges [4–7]. Nests are cohesive and may 

vary in size, or may fuse with adjacent rete ridges to produce 

bridging [4–7]. Nests predominate over single melanocytes. 

Morphologically, melanocytes may show a variable cytologic 

atypia with enlarged, hyperchromatic nuclei without involve-

ment of the upper layers of the epidermis [4–7].

Clark’s nevi can be junctional or compound, and in 

this case shows maturation of melanocytes in the dermis. 

In the papillary dermis the presence of fibroplasia may be 

observed—a variable lymphocytic infiltrate with or without 

melanophages.

The Spitz’s and Reed’s nevi are flat or papular/nodular 

pigmented or amelanotic melanocytic lesions. Different 

dermoscopic patterns have been recognized for pigmented 

(starburst: peripheral lines, peripheral globules, black-brown 

globules) or amelanotic (dotted vessels) Spitz’s nevi [8]. On 

histopathology Spitz’s nevi show a well-circumscribed, sym-

metric architecture with vertically oriented cohesive nests 

of melanocytes surrounded by clefts, epidermal hyperplasia 

with hypergranulosis, and Kamino bodies in the epidermis. 

Melanocytes are larger than those of Clark’s nevi and show an 

epithelioid (Spitz’s nevus) or pigmented spindled morphology 

(Reed’s nevus) [9–11].

Melanoma is diagnosed with dermoscopy on the basis of 

specific criteria according to different algorithms [12–14]. A 

major risk factor for developing melanoma is a high num-

ber of atypical (Clark’s, dysplastic) nevi. The aim for these 

patients is to detect early melanoma thereby reducing the 

number of unnecessary excisions. Two approaches are usually 

taken: the comparative approach and the digital follow-up. 

The former aims to recognize the signature nevus pattern, 

and the latter an asymmetric growth of suspicious lesions 

at digital follow-up, the typical behavior of melanoma [15].

Spark’s nevus is a term mainly defining a histopathologi-

cal more than a clinical entity that is underdiagnosed—or not 

always reported by most dermatopathologists though prob-

ably quite frequently present. The clinical appearance of 

Spark’s nevi is similar to those of Clark’s nevi. Dermoscopic 

features have not been described yet, and one could specu-

late that they are similar to those of Clark’s nevi because the 

histopathological architecture of Spark’s nevus is similar to 

that of a Clark’s nevus, resembling Spitz nevi in the epithelioid 

morphology of melanocytes. In our case, the lesion did not 

show peripheral lines, peripheral globules or black-brown