Pseudotumors and Cysts Assoc. Professor Jan Laco, MD, PhD

Causes of swellings of jaws Cysts odontogenic x non-odontogenic Odontogenic tumors Giant cell lesions Fibro-osseous lesions Non-odontogenic tumors of bone Metastatic tumors Chronic osteomyelitis

Cysts of jaws = pathological cavity lined by epithelium RTG: sharply-defined lucencies ± fluid slowly growth  teeth displacement asymptomatic x infection  painfull rarely: pathological fracture compressible and fluctuant swelling if extending into soft tissues appear bluish when close to mucosal surface

Cysts of jaws Odontogenic developmental inflammatory dentigerous eruption gingival lateral periodontal odontogenic keratocyst calcifying odontogenic cyst inflammatory radicular / residual inflammatory collateral (paradental)

Cysts of jaws Non-odontogenic Pseudocysts nasopalatine duct nasolabial surgical ciliated cyst Pseudocysts solitary bone “cyst“ aneurysmal bone “cyst“ Stafne´s “cyst“

Cysts of jaws – frequency (%) 1. radicular 65-70 2. dentigerous 15-20 3. keratocyst 10-20 4. nasopalatine 5-10

Radicular cyst most common swelling of jaws / cyst  males (M : F … 3 : 2) 20 - 60 years maxilla : mandible … 3 : 1 painless swelling enucleation

Radicular cyst at tip of root of tooth with necrotic pulp (caries) pulpitis  periodontitis  periapical granuloma  proliferation of Malassez nests  central liquefaction Mi: hyperplastic non-keratinizing squamous epithelium (net-like) ± hyaline (Rushton) bodies wall: granulation tissue + fibrous tissue mixed inflammation hemosiderin, cholesterol clefts ± granulomas

Odontogenic cysts residual cyst lateral radicular cyst radicular cyst left behind after tooth extraction spontaneous regress lateral radicular cyst at side of nonvital tooth lateral branch of root canal enucleation

Inflammatory collateral cyst inflammation around partially erupted tooth paradental cyst: lower M3 mandibular buccal bifurcation cyst: lower M1 and M2  males, children or adults aged 20 - 25 years vital tooth with pericoronitis Mi: ~ radicular cyst enucleation

Dentigerous (follicular) cyst cystic change of enamel organ after complete enamel formation fluid accumulation between crown and collapsed enamel organ surrounds crown + attached to tooth neck at amelo-cemental junction  crown inside (RTG) M : F … 2 : 1 20 - 50 years mandibular M3, maxillary C  prevents eruption Mi: thin squamous epithelium (2-3 layers) fibrous wall with scanty inflammation

Eruption cyst in soft tissue over tooth about to erupt from enamel organ (superficial dent. cyst) children teeth with no predecessors soft bluish swelling in gingiva spontaneously disappear

Gingival cysts newborns (Bohn´s nodules) > 80 % of newborns gingiva - proliferation of Serres nests spontaneously resolve in months midline of palate (Epstein´s pearls) adults - rare

Lateral periodontal cyst uncommon cyst beside vital tooth from nests of Malassez ? mandibular premolars Mi: thin squamous epithelium + plaque-like thickenings with clear cells (glycogen)

Lateral periodontal cyst - variants botryoid odontogenic cyst multilocular variant of LPC lower P and C, may occupy major parts of jaw, > 50 years Mi: multilocular cyst with fibrous septa squamous epithelium + clear cells (glycogen) recurrence (20 %)

Glandular odontogenic cyst (sialo-odontogenic) multilocular cyst Mi: complex squamous epithelium ~ LPC and BOC + mucous cells + intraepithelial glandular spaces recurrence (30-50 %) diff. dg.: intraosseous mucoepidermoid carcinoma

Odontogenic cysts WHO classification 2005  WHO 2017 odontogenic keratocyst  keratocystic odontogenic tumor  odontogenic keratocyst calcifying odontogenic cyst  calcifying cystic odontogenic tumor  calcifying odontogenic cyst

Odontogenic keratocyst 3rd most common cyst of jaw M > F; ~ 20-30Y + 50-70Y angle of mandible (80 %) RTG: multilocular cyst Mi: cyst – thin squamous epithelium (5-8 layers) with wavy parakeratosis ± tiny daughter cysts in wall PTCH1 gene alteration recurrence (2-25 %) within first 5 years !!! treatment: complete enucleation

Odontogenic keratocyst Gorlin-Goltz syndrome AD; PTCH gene 9q22.1-31; complete penetrance; 1 : 60,000 multiple KOT + “naevoid“ basal cell carcinomas + skeletal abnormalities + ectopic calcifications + various tumors + ocular defects Orthokeratotic cyst rare RTG: monolocular cyst Mi: orthokeratotic layer recurrence 4 %

Calcifying odontogenic cyst = Gorlin´s cyst M ~ F, ~ 5 - 92Y mandible ~ maxilla, incisor-cuspid area, gingiva Mi: cyst lined by ameloblastic epithelium ghost cells  calcification dentin recurrence (5 %) sometimes association with ameloblastoma treatment: enucleation

Odontogenic cysts RTG diff. dg. of jaw radiolucency wall thickenings anatomical structures (maxillary sinus, foramina) odontogenic cysts odontogenic tumors, part. ameloblastoma giant cell granuloma / cherubism wall thickenings cholesterol clefts + granulomas carcinoma ameloblastoma

Odontogenic cysts daily biopsy practice nonspecific findings – inflammation !!! x odontogenic keratocyst x calcifying odontogenic cyst x unicystic ameloblastoma x other cystic tumors

Nasopalatine duct cyst uncommon, often asymptomatic from nasopalatine duct epithelium midline of palate position variants (to incisive canal) nasopalatine palatine papilla median alveolar Mi: squamous + respiratory epithelium wall: mucous glands + neurovascular bundle enucleation

Nasolabial cyst = Klestadt´s, nasoalveolar very uncommon middle-aged females from remnants of nasolacrimal duct in soft tissue deep in nasolabial fold excision

Surgical ciliated cyst maxilla site of injury or operation (incl. extraction) Caldwell-Luc surgery cyst lining = mucosa of maxillary sinus respiratory epithelium enucleation

Cysts of soft tissues thyroglossal duct cyst lymphoepithelial cyst lingual dermoid mucocele

Thyroglossal duct cyst uncommon from remnants of any part of thyroglossal duct early age swelling in midline of mouth (foramen caecum) or neck Mi: squamous + respiratory epithelium wall: thyroid tissue, chronic inflammation removal + part of hyoid bone

Lymphoepithelial cyst branchiogenic cyst ??? cystic change of epithelium entrapped in LN early age lateral part of neck + mandible angle + parotid soft swelling fistula to skin / oral cavity / pharynx Mi: squamous + respiratory epithelium wall: dense lymphoid tissue + germ centres enucleation diff. dg.: cystic metastasis of SCC !!!

Sublingual dermoid developmental anomaly of branchial arches or pharyngeal pouches between hyoid and jaws or beneath tongue no symptoms Mi: epidermoid cyst – NO dermal appendages dermoid cyst – dermal appendages dissection

Mucoceles  minor salivary glands  lower lip superficial, 1 cm swellings extravasation type – damage of duct saliva leak  inflammation + mucophages NO epithelium  mucofagic granuloma retention type – obstruction of duct epithelium of dilated duct

Mucoceles ranula (Lat. “small frog“) = mucocele of submandibular or sublingual gland unilateral painless swelling, 2-3 cm floor of mouth