Calcifying epithelial odontogenic tumor (CEOT) is composed of sheets, nests, or strands of polygonal epithelial cells with abundant eosinophilic cytoplasm and variable amounts of fibrous stroma. The tumor cells have distinct cytoplasmic borders and prominent intercellular bridges. Large areas of amyloid or amyloid-like material are usually present. Calcifications develop within these amyloid-like areas and can form concentric rings known as Liesegang rings. Image courtesy of: Simon Chiosea, MD; Dept. of Pathology, Univ. of Pittsburgh, Pittsburgh, Pennsylvania, USA.