The calcifying epithelial odontogenic tumor, also known as a Pindborg tumor or CEOT, is an odontogenic tumor

Tumor

A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...

 first recognized by the Dutch pathologist Jens Jørgen Pindborg in 1955. It was previously described as an adenoid adamtoblastoma, unusual ameloblastoma

Ameloblastoma

Ameloblastoma is a rare, benign tumor of odontogenic epithelium much more commonly appearing in the lower jaw than the upper jaw. It was recognized in 1827 by Cusack...

and a cystic odontoma. Like other odontogenic neoplasms, it is thought to arise from the epithelial element of the enamel origin.

It is a typically benign and slow growing, but invasive neoplasm. Intraosseous tumors (tumors within the bone) are more likely (94%) versus extraosseus tumors (6%). It is more common in the posterior mandible of adult

Adult

An adult is a human being or living organism that is of relatively mature age, typically associated with sexual maturity and the attainment of reproductive age....

s, typically in the 4th to 5th decades. There may be a painless swelling, and it is often concurrent with an impacted tooth

Tooth

Teeth are small, calcified, whitish structures found in the jaws of many vertebrates that are used to break down food. Some animals, particularly carnivores, also use teeth for hunting or for defensive purposes. The roots of teeth are embedded in the Mandible bone or the Maxillary bone and are...

. On radiographs, it appears as a radiolucency (dark area) and is known for sometimes having small radiopacities (white areas) within it. In those instances, it is described as having a "driven-snow" appearance. Microscopically, there are deposits of amyloid

Amyloid

Amyloids are insoluble fibrous protein aggregates sharing specific structural traits. Abnormal accumulation of amyloid in organs may lead to amyloidosis, and may play a role in various neurodegenerative diseases.-Definition:...

-like material. The underlying nature of the amyloid-material is still unresolved. Clinically it has two types, the central and the peripheral. The central type of the CEOT occurs in individuals ranging in age from 20–60 years. Two-thirds of the lesions are in jaws, more commonly in the molar area with a tendency to occur in the pre-molar areas. It appears clinically to be a slowly enlarging painless mass. In the maxilla it can cause proptosis, epistaxis and nasal air way obstruction.

The peripheral type is commonly found in the anterior region of the maxilla and occurs as a soft tissue swelling.
Histopathology will reveal prominent intercellular bridges and nuclear changes such as pleomorphism, hyperchromatism and prominent nucleoli. The mitotic figures are rare. Spread throughout the epithelium and connective tissue are spherical amorhpous calcifications.

The recurrence rate for is 10-15%. Franklin and Pindborg reported a recurrence rate of 14%. It is considered to have a recurrence rate much lower than the recurrence rate for ameloblastoma

Ameloblastoma

Ameloblastoma is a rare, benign tumor of odontogenic epithelium much more commonly appearing in the lower jaw than the upper jaw. It was recognized in 1827 by Cusack...

.

Clear Cell Variant

When clear cells are present with clear cytoplasms, then this variant is referred to as "Clear Cell Variant" or CCEOT. The incidence of the clear cell variant is rare: according to this paper written in 1994, there were only 9 known cases reported in the literature. However, this indicates that approximately 8% of CEOTs contain clear cells. And Philipsen et al. indicate that 15 cases of CCEOT have been reported so far (circa 2000).

Cystic Variant

There is one case reported in the literature of a 15-year old white male with a true cystic variant of CEOT.