Oral Med Cysts Of The Oral Region

Cyst Definition - an abnormal cavity, lined by epithelium, containing fluid or semi-solid material - can be developmental and get larger in time can be found in soft tissue as well as bone Cyst Classification - based on the source of the epithelium (odontogenic cyst, non-odontogenic cyst) - based on their location (soft tissue, intrabony) Odontogenic Cyst - a cyst which the lining of the lumen is derived from epithelium produced during tooth development - can come from different parts of the odontogenic structures (Rests of Malassez, reduced enamel epithelium, dental lamina, etc) - Also Classified on their location Periapical Cyst Definition - odontogenic cyst from the Rests of Malassez, this is one of the most common cysts - located at the root apex of the tooth - the tooth must be infected or inflammed which will extend to the apical area - an odontogenic cyst of inflammatory origin that is preceeded by a chronic PA granuloma and stimulation of rests of Malassez Periapical Cyst Characteristics - PA cyst is always a radiolucency, but we cannot make a diagnosis based on the radiograph alone - we cannot determine a cyst from a chronic inflammation (apical granuloma) without histological evaluation - Failed RCT will lead to a PA cyst - one requirement is having a necrotic/infected tooth (if the tooth is intact, this will be some other pathology) Periapical Cyst Treatment - apical surgery is necessary to remove the cyst and then retrofill the lesion - if the tooth is not salvagable, then we must remove the retained root and remove the cyst otherwise it will turn into a residual cyst - note that histologically there are inflammatory cells and a capsule surrounding an epithelial layer with a lumen on the interior Rushton Bodies - these are eiosinophilic bodie which result from degenerative changes in cells in some (not all) of the cystic lesions - this is an indication of the longevity of a chronic lesion Residual Cyst - this develops from an untreated radicular cyst - we must curate the lesion otherwise it will lead to a residual cyst Dentigerous Cyst (Follicular Cyst) - this is an odontogenic cys (from the developmental structures of the tooth) which surrounds the crown of an impacted tooth - caused by fluid accumulation between the reduced enamel epithelium and enamel surface resulting in a cyst - this is a pericoronal cyst of an impacted tooth - lined by non-keratinized epithelium (could be inflammed or not) Eruption Cyst - this is an odontogenic cyst with the histologic features of a dentigerous cyst that surrounds a tooth's crown that has erupted through the bone but NOT the soft tissue - clinically is visible as a soft fluctuant mass on the alveolar ridges - found in children who are in the process of erupting their teeth - possible to have a blue-ish color due to trauma and bleeding with pigments (hemosiderin) Odontogenic Keratocyst (OKC) - cyst derived from the remnants, rests of the dental lamina with a biologic behavior similar to a benign neoplasm - distinct lining of 6-10 cells in thickness that exhibits a basal cell layer of palisaded cells and a surface of corrugated parakeratin - they can be found anywhere in the mouth, when around the root of a tooth they can cause resorption of the bone Odontogenic Keratocyst Characteristics - this has histologically keratinized epithelium, thus if you look at the lumen of the OKC it will be filled with a cheezy material (keratin) - have a uniform thickness with a flat basal membrane, no rete pegs, and a 7-8 cell layer - not usually inflamed, not irritated - also might see a micro-cyst or a daughter/satellite cyst in the cell wall of the OKC (leading to an increased probability of recurrence OKC in Basal Cell Carcinoma Syndrome - most of the OKC are single and thus if there are multiple present we must think of BCC syndrome - also present with bifid ribs, pitting of the skin, CV problems, intracranial tumors - complexity of the syndrome leads to a treatment of individual problems but not of the syndrome - dentist is usually first to diagnose syndrome due to the presence of multiple OKC Lateral Periodontal Cyst - a slow-growing, non-expansive developmental odontogenic cyst derived from one or more rests of the dental lamina containing an embryonic lining of 1-3 cuboidal cells and distinctive focal thickenings (plaques) - found between two adjacent teeth in the bone, common in the posterior mandible, rarely change shape and lined by NON-keratinized Butryoid Odontogenic Cyst - a type of lateral periodontal cyst that shows a multilocular growth pattern (looks grapelike) - these are many cystic cavities which are lined by the same epithelium as the lateral periodontal cysts Gingival Cyst of the Adult - a small developmental odontogenic cyst of the gingival soft tissue derived from the rests of the dental lamina - contains a lining of the embryonic epithelium of cuboidal cells and distinctive focal thickenings similar to the lateral periodontal cysts - this lesion is in the soft tissue rather than in bone - asymptomatic, slow growing, but may gradually cause bone resorption due to pressure Dental Lamina (Gingival) Cyst of the Newborn - also called Epstein Pearl or Bohn's Nodule - uncommon superficial raised nodules on the edentulous ridge of infants that resolve without treatment - derived from the rests of the dental lamina and consisting of keratin-producing epithelial cells Glandular Odontogenic Cyst (Sialo-Odontogenic Cyst) - an unusually large solitary or multi-locular odontogenic cyst most likely from the rests of dental lamina - stratified squamous epithelium containing numerous mucus-secreting cells - these present as radiolucencies, several mucus-producing cavities right next to each other Paradental Cyst - a cyst of uncertain origin found primarily on the distal or facial aspect of a vital mandibular third molar consisting of intensely inflamed CT and epithelial lining Nasopalatine Duct Cyst - an intraosseous developmental cyst of the midline of the anterior palate, derived from the islands of epithelium remaining after the closure of the embryonic nasopalatine duct - lesion (when large) tend to be symptomatic due to pressure and inflammation - these are around vital teeth which respond normally to testing - cysts may have nerves and vessels due to size Nasolabial Cyst - a developmental cyst of the soft tissue of the anterior mucobuccal fold beneath the ala of the nose - most likely derived from the remnants of the inferior portion of the nasolacrimal duct - requires surgical removal, non-odontogenic cyst seen in the upper lip area Lymphoepithelial Cyst - a cyst with a lumen lined by a keratinizing stratified squamous epithelium and a capsule containing multiple normal lymphoid follicles and a dense accumulation of the normal lymphocytes - smaller lesions in the oral cavity, larger aspect in the lateral neck Oral Lymphoepithelial Cyst - a lymphoepithelial cyst commonly located intraorally on the posterior lateral tongue and the anterior floor of the mouth - the cavity is lined by keratininzed epithelium with lymphoid tissue under the surface (germinal center) Cervical Lymphoepithelial Cyst - also called a branchial cleft cyst - an unusually large lymphoepithelial cyst located on the lateral aspect of the neck - upon removal we see a cavity with lymphoid tissue with the same tissue as that in the lymph nodes, this should be removed Thyroglossal Duct Cyst - a cyst located above the thyroid gland and beneath the base of the tongue - lumen is lined with a mixture of epithelial cell types derived from the remnants of the embryonic thyroglossal tract, often containing thyroid tissue in the capsule - upon removal it resembles thyroid tissue histologically Dermoid Cyst - cyst of the midline of the upper neck or anterior floor of the mouth of young patients, derived from the remnants of the embryonic skin - consists of a lumen lined by a keratinized stratified squamous epithelium and containing one or more skin appendages (hair, sweat, sebasceous glands) - lesions that are lined by epithelium containing another misplaced (ectopic) demoid substance - location of the cyst depends on its relation to the mylohyoid muscle Epidermoid Cyst - a cyst of skin with a lumen lined by keratinizeing stratified squamous epithelium, usually filled with keratin and without skin appendages in the capsule wall - similar to the dermoid cyst, but we do not see appendages - keratin filled cyst with no appendages Surgical Ciliated Cyst of the Maxilla - an intrabony cyst located near the floor of the maxillary sinus lined by a pseudostratified ciliated columnar epithelium, caused by implantation of normal mucus secreting sinus epithelium during surgery - in maxilla when surgical perforation happens placing a portion of the epithelium into the bone of the maxilla resulting in a cyst Heterotopic Oral Gastrointestinal Cyst - a rare and unusual developmental cyst commonly found in the tongue or floor of the mouth of infants or young children - histologically looks like it has features of the GI