Dermatology: Practical and Conceptual


Image Letter  |  Dermatol Pract Concept 2020;10(4):2020090 1

Dermatology Practical & Conceptual

Case Presentation

A 57-year old man with known multiple atypical nevi pre-

sented for his regular yearly follow-up visit. He had no 

history of personal or familial melanoma. During the visit, 

we observed a roundish, well-demarcated, nodular lesion 

with a diameter of 8 mm on his right flank. A shiny surface, 

some scales at the periphery and clinically visible vessels were 

observed.  The lesion was firm on palpation. On dermoscopy, 

the lesion presented a polymorphic vascular pattern (lin-

ear-irregular, glomerular, and hairpin vessels), blue-reddish 

lacunae randomly distributed over the lesion as well as some 

hemorrhagic crusts (Figure 1, A and B).

The nodule was excised, and histopathology showed an 

irritated seborrheic keratosis with reactive atypia. 

Teaching Point

Seborrheic keratoses, especially irritated lesions, present in a 

huge morphological variety clinically and dermoscopically. 

These lesions can exhibit features suggestive of amelanotic 

melanoma, Merkel cell carcinoma (eg, polymorphic vessels), 

or basal cell carcinoma and require histological examina-

tion [1,2]. 

References

1.  Carrera C. The many faces of seborrheic keratosis. Actas 

Dermosifiliogr. 2019;110(5):338. DOI: 10.1016/10.1016/j.

ad.2018.12.005. 

2.  Carrera C, Segura S, Aguilera P, et al. Dermoscopic clues for 

diagnosing melanomas that resemble seborrheic keratosis. JAMA 

Dermatol. 2017;153(6):544-551. DOI: 10.1016/10.1001/jama-

dermatol.2017.0129. PMID: 28355453.

Polymorphic Vessels–Think About Seborrheic 
Keratosis

Teresa Deinlein1, Elena Eber1, Regina Fink-Puches1, Rainer Hofmann-Wellenhof1

1 Department of Dermatology and Venereology, Medical University of Graz, Austria

Key words: seborrheic keratosis, melanoma, dermoscopy, polymorphic vessels

Citation: Deinlein T, Eber E, Fink-Puches, Hofmann-Wellenhof R. Polymorphic vessels—think about seborrheic keratosis. Dermatol Pract 
Concept. 2020;10(4):e2020090. DOI: https://doi.org/10.5826/dpc.1004a90

Accepted: May 25, 2020; Published: October 26, 2020

Copyright: ©2020 Deinlein et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License 
BY-NC-4.0, which permits unrestricted noncommercial 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.

Authorship: All authors have contributed significantly to this publication.

Corresponding author: Rainer Hofmann-Wellenhof, MD, Department of Dermatology and Venereology, Medical University of Graz, 
Auenbruggerplatz 8, 8036 Graz, Austria. Email: rainer.hofmann@medunigraz.at



2 Image Letter  |  Dermatol Pract Concept 2020;10(4):2020090

Figure 1. (A) Clinical image 

showing a roundish, well- 

demarcated red nodule with a 

maximum diameter of 8 mm. 

Additionally, a shiny surface, 

some peripheral scales, and 

different types of vessels are 

observable. (B) On dermoscopy, 

a polymorphic vascular pattern 

composed of linear-irregular, 

glomerular, and hairpin ves-

sels is evident. Moreover, blue- 

reddish lacunae and hemor-

rhagic crusts are seen.

A B