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radicular cyst

Monday 26 October 2009

periapical cyst / inflammatory odontogenic cyst d/t non-vital tooth)

Definition: Radicular cysts are located at the root tips of teeth in which the dental pulp is necrotic, mostly due to dental caries.

See also : odontogenic cysts , cysts of the jaws

A periapical cyst, also known as a radicular cyst, is inflammatory, develops from a periapical granuloma, and is associated with the root of a tooth. It is most common in the anterior maxilla. It shows a stratified squamous epithelium and fibrous capsule with mixed (mostly acute) inflammation. It is the most common odontogenic cyst, and most common cyst of the jaw.

Images

- Radicular cyst (periapical cyst / inflammatory odontogenic cyst d/t non-vital tooth)

- Cholesterol crystal clefts and foreing-body giant cells found in radicular cysts.

- Rushton bodies in periapical cyst / radicular cyst

Digital cases

- JRC:8595 : Radicular cyst

Subsequent chronic inflammation in the adjacent jaw area causes growth of the epithelial rests of Malassez present in that area.

Subsequent central liquefaction necrosis of these enlarged epithelial rests results in formation of a cyst that is lined by non-keratinizing squamous epithelium.

This epithelium is usually spongiotic and infiltrated by inflammatory cells. Within the cyst epithelium, hyaline bodies of various sizes and shapes may be present, the so-called Rushton bodies.

Occasionally, the lining squamous cells are admixed with mucous cells or ciliated cells.

In terms of differential diagnosis, an identical histology may be shown by other jaw cysts, both of the odontogenic as well as of the non-odontogenic category in particular when there are extensive inflammatory changes in the cyst wall.

Therefore, the diagnosis of a radicular cyst depends on the association of the cyst with a decayed tooth and not on the presence of characteristic histological features.

When a radicular cyst is left behind in the jaw after extraction of the causative tooth, it is called a residual cyst.

Differential diagnosis

- cysts of the jaws : maxillary cysts / mandibular cysts

References

- Lesions of the jaws. Slootweg PJ. Histopathology. 2009 Mar;54(4):401-18. Epub 2008 Jul 11. PMID: 18637149