Rosettes

From dermoscopedia

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 Editor: Ralph P. Braun

 Author(s): Ralph P. Braun
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Description This chapter describes the histopathological correlation of the dermoscopyThe examination of [skin lesions] with a 'dermatoscope'. This traditionally consists of a magnifier (typically x10), a non-polarised light source, a transparent plate and a liquid medium between the instrument and the skin, and allows inspection of skin lesions unobstructed by skin surface reflections. Modern dermatoscopes dispense with the use of liquid medium and instead use polarised light to cancel out skin surface reflections. term rosettesFour bright white dots or clods arranged together as a square (or a four leaf clover)
Author(s) Ralph P. Braun
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Status update July 2, 2018
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RosettesFour bright white dots or clods arranged together as a square (or a four leaf clover) (also known as ‘four-clod dotsDots are small, round structures of less than 0.1 mm in diameter that have a red color when corresponding to blood vessels; however, when due to melanin, their color ranges from black, brown, to blue-gray depending on the depth and concentration of the melanin in the skin (Tyndall effect).’) are defined as four white points, arranged as a four leaf clover. They are not lesion-specific and are described in many tumoral and inflammatory lesions, including: scars, dermatofibromaDermatofibromas are hard solitary slow-growing papules (rounded bumps) that may appear in a variety of colours, usually brownish to tan; they are often elevated or pedunculated. A dermatofibroma is associated with the dimple sign; by applying lateral pressure, there is a central depression of the dermatofibroma., actinic keratosisActinic keratosis (also called solar keratosis and senile keratosis; abbreviated as AK) is a pre-cancerous patch of thick, scaly, or crusty skin., squamous cell carcinomaThis glossary term has not yet been described. and melanomaThis glossary term has not yet been described. and more. Smaller rosettes are mainly caused by polarizing horny material at infundibular level in adnexal openings and larger rosettes mainly by concentric perifollicular fibrosis [1].


  1. Haspeslagh et al.: Rosettes and other white shiny structures in polarized dermoscopy: histological correlate and optical explanation. J Eur Acad Dermatol Venereol 2016;30:311-3. PMID: 25786770. DOI.