Calcifying epithelial odontogenic tumor, also known as Pindborg tumor, is a rare odontogenic tumor characterized by amyloid-like material deposition and calcifications. Histologically, cords and islands of epithelial cells are embedded in a fibrous stroma, surrounded by an amorphous amyloid-like material (that stains with Congo red). The epithelial cells are polyhedral with abundant eosinophilic cytoplasm. Scattered dense concentric calcifications can be seen. There is no cystic component (Thompson).

As a side note, calcifying cystic odontogenic tumor (a tumor with a similar name which is also known as calcifying odontogenic cyst or Gorlin cyst) is a cystic tumor with an ameloblastoma-like epithelium, ghost cells and calcifications.

Average age is 40 (range 20-60) with equal gender predilection. The majority of cases arise in the mandible, and a subset (~5%) are peripheral (extraosseous), arising in the gingiva.

Recurrence rate is 15%, rare reports of malignant transformation.