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What is Hairpin shaped eosinophilic structure present in radicular cyst is: and explain in detail?
Periapical Cyst 
The cyst lumen may be filled with fluid and cellular debris. On occasion, the lining epithelium may demonstrate linear or arch-shaped calcifications known as Rushton bodies 
Squamous epithelial cyst lining exhibiting numerous irregular and curvilinear Rushton bodies.