Pindborg Tumor : Microscopic
Calcifying epithelial odontogenic tumor (CEOT) showing tumor cells with abundant eosinophilic cytoplasm arranged in small sheets and strands. Oval, round, or irregular deposits of amyloid-like material with foci of calcification are initimately associated with the tumor cells. Odontogenic Ameloblast-Associated Protein (ODAM): The amorphous, eosinophilic, hyalinized extracellular material seen in CEOT stains like amyloid with Congo red and shows apple-green birefringence under polarized light. This material has been designated as odontogenic ameloblast-associated protein (ODAM) and is produced by normal odontogenic apparatus as well as odontogenic tumors. It is considered to be a developmental antigen that plays an essential role in tooth maturation as well as in the pathogenesis of certain odontogenic and epithelial neoplasms. Image courtesy of: Bin Xu, MD, PhD, Dept. of Pathology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.