Dermoscopic rainbow pattern: A strong clue to malignancy or just a light show?
- PMID: 33163886
- PMCID: PMC7603844
- DOI: 10.14744/nci.2020.32656
Dermoscopic rainbow pattern: A strong clue to malignancy or just a light show?
Abstract
Objective: Rainbow pattern is a dermoscopic finding composed of multiple colors simulating a rainbow. It is known as a characteristic feature of Kaposi's sarcoma. Here, we reported different non-Kaposi's sarcoma conditions with a rainbow pattern aiming to discuss the diagnostic significance of the finding.
Methods: In this multicenter study, dermoscopic images of the non-Kaposi's sarcoma lesions having a histopathological diagnosis were reviewed for the presence of a rainbow pattern. Dermoscopic examination was performed by a polarized handheld dermoscope with x10 magnification.
Results: A total of 840 lesions were reviewed and 21 (2%) non-Kaposi sarcoma lesions having dermoscopic rainbow pattern were detected. These lesions were as follows; pyogenic granuloma (n=4, 19%), hypertrophic scar (n=4, 19%), basal cell carcinoma (n=2, 10%), dermatofibroma (n=2, 10%), angiokeratoma (n=2, 10%), blue nevus (n=1, 5%), granuloma annulare (n=1, 5%), strawberry angioma (n=1, 5%), epidermal cyst (n=1, 5%), malignant melanoma (n=1, 5%), dissecting cellulitis (n=1, 5%) and subungual hematoma (n=1, 5%). The most common localization was limb (n=14, 67%) followed by face (n=3, 14%).
Conclusion: We suggest that the rainbow pattern is a complex and quite unspecific optic phenomenon which can be seen both in vascular and non-vascular lesions. Its diagnostic significance should be considered in the context of the other structural dermoscopic finding. To the best of our knowledge, to our knowledge, this is the most comprehensive study focusing on rainbow pattern in non-Kaposi's sarcoma lesions. Here, we also reported rainbow pattern in dissecting cellulitis, granuloma annulare and subungual hematoma which has not been shown to have rainbow pattern previously.
Keywords: Dermoscopy; Kaposi’s sarcoma; optic phenomenon; rainbow pattern.
Copyright: © 2020 by Istanbul Northern Anatolian Association of Public Hospitals.
Conflict of interest statement
Conflict of Interest: No conflict of interest was declared by the authors.
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References
-
- Hu SC, Ke CL, Lee CH, Wu CS, Chen GS, Cheng ST. Dermoscopy of Kaposi's sarcoma:areas exhibiting the multicoloured 'rainbow pattern'. J Eur Acad Dermatol Venereol. 2009;23:1128–132. - PubMed
-
- Cheng ST, Ke CL, Lee CH, Wu CS, Chen GS, Hu SC. Rainbow pattern in Kaposi's sarcoma under polarized dermoscopy: a dermoscopic pathological study. Br J Dermatol. 2009;160:801–9. - PubMed
-
- Vázquez-López F, García-García B, Rajadhyaksha M, Marghoob AA. Dermoscopic rainbow pattern in non-Kaposi sarcoma lesions. Br J Dermatol. 2009;161:474–5. - PubMed
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