Dermatology: Practical and Conceptual


Image Letter | Dermatol Pract Concept. 2022;12(3):e2022139 1

Dermatology Practical & Conceptual

A Case of Melanoma in a Patient With Psoriasis 
Highlighting the Importance of Dermatoscopy  

and Inflammoscopy 
Sarah Benton1, Lori Ann Fiessinger1, Juan Pablo Jaimes1

1 Department of Dermatology, University of Minnesota Medical School, Minneapolis, Minnesota, USA 

Citation: Benton S, Fiessinger LA, Jaimes JP. A case of melanoma in a patient with psoriasis highlighting the importance of dermatoscopy  
and inflammoscopy. Dermatol Pract Concept. 2022;12(3):e2022139. DOI: https://doi.org/10.5826/dpc.1203a139

Accepted: December 27, 2021; Published: July 2022

Copyright: ©2022 Benton et al. This is an open-access article distributed under the terms of the Creative Commons Attribution-
NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use, 
distribution, and reproduction in any medium, provided the original authors and source are credited.

Funding: None.

Competing interests: None.

Authorship: All authors have contributed significantly to this publication

Corresponding author: Juan P Jaimes, MD, MS, Department of Dermatology, University of Minnesota Medical School, 516 Delaware St SE 
Suite 4-240, Minneapolis, MN 55455, USA E-mail: jaim0004@umn.edu

Case Presentation 

A male patient in his fourth decade of life presented to the 

clinic for evaluation of psoriasis. Dermatoscopy of a lesion 

on the right posterior upper arm that clinically resembled 

a psoriasiform papule showed numerous polarizing-specific 

white lines and polymorphous vessels (Figures 1, A-C). Der-

matoscopy of nearby papules and plaques of psoriasis re-

vealed white scale on a background of randomly distributed 

dotted and coiled vessels (Figure 1D). The lesion in Figure 

1A was sent for histological analysis and found to be a ma-

lignant melanoma with a Breslow depth of 0.7 mm, occur-

ring in association with a nevus.  

Teaching Point

Though clinically the melanoma resembled a psoriatic 

papule, under dermatoscopy the lesion appeared very 

different from other psoriatic lesions and had features of 

melanoma. This highlights the importance of dermatos-

copy and inflammoscopy in the diagnosis of neoplasms 

and inflammatory conditions. The most common derma-

toscopic pattern of psoriasis is erythematous background 

with evenly distributed red dots and white scale [1]. Polar-

izing specific white lines and polymorphous vessels, clues 

that can be seen in melanoma, would not be expected in 

psoriasis [2].



2 Image Letter | Dermatol Pract Concept. 2022;12(3):e2022139

Figure 1. (A) Clinical image of the patient right upper arm with scattered pink papules and plaques with overlying white scale. (B) Close-up 

image of the patient right upper posterior arm showing an 8 mm erythematous papule with white scale. (C) Dermatoscopic view showing 

many polarizing-specific white lines and polymorphous vessels (polarized dermatoscopy). (D) Dermatoscopic view of nearby psoriasis show-

ing white scale on a background of randomly distributed dotted and coiled vessels (polarized dermatoscopy).

Informed consent: Written informed consent for publication of 
clinical details and clinical images was obtained from the patient.

References

1. Sgouros D, Apalla Z, Ioannides D, et al. Dermoscopy of Com-

mon Inflammatory Disorders. Dermatol Clin. 2018;36(4): 

359-368. DOI: 10.1016/j.det.2018.05.003. PMID: 30201145.

2. Balagula Y, Braun RP, Rabinovitz HS, et al. The significance of 

crystalline/chrysalis structures in the diagnosis of melanocytic and 

nonmelanocytic lesions. J Am Acad Dermatol. 2012;67(2):194.

e1-194.e8. DOI: 10.1016/j.jaad.2011.04.039. PMID: 22030020.