Rosettes in actinic keratosis and squamous cell carcinoma: distribution, association to other dermoscopic signs and description of the rosette pattern

• Published in: Journal of the European Academy of Dermatology and Venereology Vol. 32; no. 1; pp. 48 - 52
• Main Authors: Lozano‐Masdemont, B., Polimón‐Olabarrieta, I., Marinero‐Escobedo, S., Gutiérrez‐Pecharromán, A., Rodríguez‐Lomba, E.
• Format: Journal Article
• Language: English
• Published: England 01-01-2018
• ISSN: 0926-9959; 1468-3083
• DOI: 10.1111/jdv.14474

Background
Rosettes, a dermoscopic structure characterized by four white points arranged as a 4‐leaf clover, supports the dermoscopic diagnosis of actinic keratosis (AK) or squamous cell carcinoma (SCC).
Objective
The association of rosettes with other dermoscopic structures in AK or SCC and their distribution has not been analysed yet.
Methods
We conducted a prospective study of patients with histologically proven AK or SCC who presented dermoscopic rosettes at initial evaluation.
Results
A total of 56 tumours were collected (94.6% AK and 5.4% SCC). Thirty‐seven (66.1%) lesions were non‐pigmented and 19 (33.9%) pigmented. The most common dermoscopic findings were erythema (53; 94.6%) and scale (42; 75%). White circles were present in 21 lesions (37.5%); pigmented pseudonetwork in 18 (32.1%) and multiple grey to brown dots and globules in 14 (25%). Rosettes were distributed focally in 9 (16.1%) and generalized in 47 (83.9%). The rosette pattern (rosettes as the main structure) was observed only in AK (19; 35.8%).
Limitations
The analysis was not blinded. The distinction between focal distribution (up to 3 rosettes) or generalized could be considered arbitrary.
Conclusion
The rosette pattern identified in AK may be a specific pattern for AK.