Pseudotumors and Cysts

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

2. 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

3. 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

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

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

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

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

8. 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

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

10. 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

11. 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

12. 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

13. 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

14. 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)

15. 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 %)

16. 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

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

18. 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

19. 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 %

20. 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

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

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

23. 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

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

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

26. Cysts of soft tissues • thyroglossal duct cyst • lymphoepithelial cyst • lingual dermoid • mucocele

27. 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

28. 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 !!!

29. 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

30. 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

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