Dermatology: Practical and Conceptual


244 Letter  |  Dermatol Pract Concept 2018;8(3):18

DERMATOLOGY PRACTICAL & CONCEPTUAL
www.derm101.com

Giant Clear Cell Acanthoma with  
Dermatoscopic White Lines

Omid Zargari1, Seyyede Zeinab Azimi2, Siamak Geranmayeh3

1 Dermatology, Dana Clinic, Rasht, Iran

2 Department of Dermatology, Guilan University of Medical Sciences, Rasht, Iran

3 Sina Pathobiology Laboratory, Rasht, Iran

Key words: clear cell acanthoma, dermatoscopy, epidermal tumor

Citation: Zargari O, Azimi SZ, Geranmayeh S. Giant clear cell acanthoma with dermatoscopic white lines. Dermatol Pract Concept. 
2018;8(3):244-246. DOI: https://doi.org/10.5826/dpc.0803a18

Received: December 9, 2017; Accepted: February 2, 2018; Published: July 31, 2018

Copyright: ©2018 Zargari 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: Seyyede Zeinab Azimi, MD, Department of Dermatology, Guilan University of Medical Sciences, Razi Hospital, 
Rasht, Iran, 41448. Email: sz.azimi@yahoo.com.

Introduction

Clear cell acanthoma (CCA) was first described by Degos 

in 1962 [1] and has been referred to as Degos’ acanthoma. It 

is a benign epidermal tumor that commonly emerges as a soli-

tary dome-shaped lesion on the legs with no gender predilec-

tion [1]. However, eruptive forms and involvements of other 

areas such as inguinal region, scrotum, vermilion mucosa, 

scalp, palm, nipple, and hallux have been reported [2,3].

Case Presentation

A 73-year-old Caucasian man presented with an asymptom-

atic strawberry-like plaque on his right ankle, reportedly 

present for several years. The plaque was approximately 4 cm 

in diameter, colored red and purple, and surrounded by a 

fine collarette of scale (Figure 1). There was no history of 

pigmented skin changes or melanoma among his family 

members. Past medical history was notable for ischemic 

heart disease, diabetes mellitus, and hypertension. His regu-

lar medications included aspirin, warfarin, metformin, and 

atorvastatin.

Dermatoscopic examination revealed a variegated red/

purple-colored lesion with curved white lines and with dot 

vessels in a serpiginous (“string of pearls”) pattern (Fig-

ure 2). There were no colors to indicate melanin (black, 

Figure 1. An asymptomatic erythematous vascular plaque on right 

ankle present for several years. [Copyright: ©2018 Zargari et al.]

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Inserted Text
Skin Research Center, Department of Dermatology, Razi Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran

zenaidavega
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Letter  |  Dermatol Pract Concept 2018;8(3):18 245

tumor, a more recent hypothesis sug-

gests that CCA is a reactive inflamma-

tory dermatosis [5]. The higher inci-

dence of CCA in lower limbs of elderly 

patients favors a reactive nature, prob-

ably induced by stasis dermatitis [6].

Shalin et al demonstrated that the 

concurrence of CCA with syringofibro-

adenomatous changes also suggests that 

both of these entities may share deriva-

tion from the eccrine apparatus [7]. The 

clinical variants of CCA include giant, 

polypoid or pedunculated, pigmented, 

eruptive, atypical, and cystic patterns 

[8]. The giant type of CCA measures 

more than 40 mm. Until now, there are 

only 5 reports of giant CCA in the Eng-

lish literature, these being located on 

the foot, buttock, and perineum. Due 

to the variable clinical presentations 

of CCA, it frequently is mistaken for 

several other lesions, including Bow-

en’s disease, squamous cell carcinoma, 

malignant melanoma, Kaposi sarcoma, 

and angiosarcoma [9,10].

Indeed, the diagnosis is rarely made 

before skin biopsy, and frequently it 

can be misdiagnosed. Dermatoscopy 

can improve the accuracy in diagnosing 

CCA [9,11]. The dermatoscopic pattern 

of CCA was first described by Blum 

in 2001 as partly homogenous, symmet-

rically or bunch-like arranged pinpoint-

like capillaries [12]. CCA usually has a 

brown, gray, or blue). A biopsy was 

performed. Histopathological exami-

nation showed an acanthotic epidermis 

with pale-appearing keratinocytes full 

of a glycogen-rich cytoplasm positive 

to periodic-acid-Schiff (PAS) staining, 

consistent with CCA (Figure 3). The 

lesion was treated with cryotherapy and 

curettage. In follow-up, the patient had 

not developed new CCAs after 1 year.

Discussion

CCA is frequently presented as a soli-

tary, slowly growing nodule or plaque 

on the legs of elderly persons. Its size 

usually varies from 3 to 20 mm [4]. 

Perhaps, the original description of Fine 

and Chernosky is still the most com-

prehensive one: “CCA has the stuck on 

appearance of seborrheic keratosis, the 

vascular look of pyogenic granuloma, 

the scale and exudation of an eczema-

tous process and advancing rounded 

border of an epithelioma” [4].

The pathogenesis of CCA remains 

unknown. There is not significant evi-

dence to support a traumatic or drug-

induced origin. Although it was primar-

ily considered to be a benign epidermal 

Figure  2. Dermoscopy of the lesion shown 

in Figure 1 showing a variegated red/purple-

colored lesion with curved white lines and 

with dot vessels in a serpiginous pattern. 

[Copyright: ©2018 Zargari et al.]

Figure 3. Dermatomicrographs of the lesion in Figures 1 and 2. (A) Hematoxylin and eosin 

(H&E) stain demonstrating pale-appearing cytoplasm of plump keratinocytes with elongat-

ed rete ridges. (B) Pale keratinocytes full of a glycogen-rich cytoplasm positive to periodic- 

acid-Schiff (PAS) staining. (Original magnification: H&E stain ×100, PAS ×40). [Copyright: 

©2018 Zargari et al.]

unique appearance on dermatoscopy, 

characterized by red dots, globules, 

and, sometimes, coiled (glomerular) ves-

sels, arranged in a serpiginous pattern. 

When fully developed, these serpiginous 

arrangements are strikingly symmetric. 

However, in some cases the serpiginous 

vascular pattern is incomplete or partly 

developed, either showing a forme fruste 

or a compression artifact but is still 

clearly recognizable.

Dot or coiled (glomerular) vessels 

can also be a characteristic of inflamma-

tory dermatoses, such as psoriasis, pity-

riasis lichenoides, and discoid eczema. 

Nevertheless, in these diseases, the red 

dots or coiled vessels are uniformly dis-

tributed and do not join together to 

form serpiginous vascular arrays [12-

16]. Other uncommon dermatoscopic 

features of CCA include the presence of 

areas of hemorrhage, orange crusts, and 

a peripheral collarette of translucent 

scales. A new finding recently described 

in the literature is the frequent presence 

of crystalline structures when polarized 

dermatoscopy is used for the evaluation 

of CCA [17].

CCA is a benign tumor, and when 

the diagnosis can be made with con-

fidence due to the characteristic ser-

piginous vascular pattern, treatment is 

not indicated for small asymptomatic 

lesions. If treatment is desired, surgical 



246 Letter  |  Dermatol Pract Concept 2018;8(3):18

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excision may be the treatment of choice for single lesions. 

However, cryosurgery remains a very useful alternative, espe-

cially for multiple lesions [10].

Conclusions

Giant forms of CCA are extremely rare and confident clini-

cal diagnosis is not always possible. Despite the nonspecific 

clinical presentation, the giant CCA reported herein had the 

known specific dermatoscopic feature of dot vessels distrib-

uted in a serpiginous arrangement as well as a new feature of 

curved white lines, not previously reported.

References

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jaad.2016.02.203.

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hallux: the first case report. J Eur Acad Dermatol Venereol. 

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