This document discusses three odontogenic tumors: adenomatoid odontogenic tumor, calcifying epithelial odontogenic tumor, and odontogenic myxoma. It provides information on the classification, histopathological features, clinical presentation, diagnosis and treatment of each tumor type. The key points are that adenomatoid odontogenic tumor commonly occurs in younger patients, presents as a radiolucent lesion associated with an unerupted tooth, and has a benign clinical course. Calcifying epithelial odontogenic tumor is characterized by islands of epithelial cells surrounded by amyloid-like calcified material. Odontogenic myxoma presents as an expansile radiolucent lesion containing myxoid tissue.

2. ADENOMATOID ODONTOGENIC TUMOR,
CALCIFYING EPITHELIAL ODONTOGENIC TUMOR, ODONTOGENIC MYXOMA
Presented by
Dr.D.Venkatesh Kumar

3. CONTENTS
 INTRODUCTION
 CLASSIFICATION
 ADENOMATOID ODONTOGENIC TUMOR
 CALCIFYING EPITHELIAL ODONTOGENIC TUMOR (PINDBORG TUMOR)
 ODONTOGENIC MYXOMA
 CONCLUSION
 REFERENCES

4. INTRODUCTION
Tumors derived from the odontogenic tissues constitute an unusually diverse group
of lesions.
This multiformity reflects the complex development of the dental structures,
since these tumors all originate through some aberration from the normal pattern
of odontogenesis.

5. WHO-Classification-2003
ODONTOGENIC EPITHELIUM
WITHOUT ODONTOGENIC
ECTOMESENCHYME
•Ameloblastoma –
solid/multicystic
•Ameloblastoma –
extraosseous/peripheral
•Ameloblastoma – desmoplastic
•Ameloblastoma - unicystic
•Squamous odontogenic tumour
•Calcifying epithelial odontogenic
tumour
•Adenomatoid odontogenic
tumour
•Keratocystic odontogenic tumour
ODONTOGENIC EPITHELIUM WITH
ODONTOGENIC ECTOMESENCHYME
WITH OR WITHOUT HARD TISSUE
FORMATION
•Ameloblastic fibroma
•Ameloblastic fibrodentinoma
•Ameloblastic fibro-odontome
•Calcifying cystic odontogenic
tumour
•Dentinogenic ghost cell tumour
•Odontoameloblastoma
•Odontomes - complex and
compound
ODONTOGENIC
ECTOMESENCHYME WITH OR
WITH OUT INCLUDED
ODONTOGENIC EPITHELIUM
•Cementoblastoma
•Odontogenic Fibroma
•Odontogenic Myxoma or
fibromyxoma

6. WHO-Classification-2017
EPITHELIAL TUMORS
•Ameloblastoma
•Ameloblastoma,
unicystic type
•Ameloblastoma,
extraosseous/
peripheral type
•Metastasizing
(malignant)
ameloblastoma
•Squamous odontogenic
tumour
•Calcifying epithelial
odontogenic tumour
•Adenomatoid
odontogenic tumour
MESENCHYMAL TUMORS
•Ameloblastic fibroma
•Odontoma
•Odontoma, compound
type
•Odontoma, complex
type
•Dentinogenic ghost cell
tumour
•Primordial odontogenic
tumour
MIXED ODONTOGENIC
TUMORS
•Odontogenic fibroma
•Odontogenic
myxoma/myxofibroma
•Cementoblastoma
•Cemento-ossifying
fibroma

7. ADENOMATOID ODONTOGENIC TUMOR
HISTOLOGIC DEFINATION:
A hamartomatous lesion of odontogenic epithelium producing solid nodules of
cuboidal or columnar cells, here and there forming convoluted bands arranged in
complicated patterns. Throughout the lesion the cells form structures of
tubular or ductlike appearance. The lesion may be partly cystic with the solid
tumorous tissue constituting part of large cyst wall. The fibrous connective
stroma is rather sparse and may contain dysplastic dentinoid as well as calcified
material that may be quite extensive.

8.  AOT-3% - 7%-all odontogenic tumors
 Lesion-formerly considered-variant-ameloblastoma & designated
as “adenoameloblastoma-1905-1969,
 1969-PHILIPSEN and BIRN introduce term adenomatoid
odontogenc tumor
 Investigators-suggested-lesion arises-remnants of dental lamina.

9. Forms of AOT

10. CLINICAL AND RADIOGRAPHIC FEATURES:
 Younger patients & 2/3rd -10 to 19 years of age.
 Anterior portions of the maxilla.
 Female prediliction.
 Small, sessile masses-facial gingiva-maxilla.
 Clinically-cannot be differentiated-common gingival fibrous lesions.
 Asymptomatic-routine radiographic examination.
 Larger lesions-painless expansion of the bone.

11.  75% of cases-circumscribed, unilocular radiolucency-crown -
unerupted toot- canine.
 Follicular type AOT-impossible to differentiate radiographically -
dentigerous cyst.
 Less often-well-delineated unilocular radiolucency-not related -
unerupted tooth-located between-roots of erupted teeth
(extrafollicular type).

12.  The lesion-completely radiolucent-however, fine (snowflake)
calcifications. This feature may be helpful in differentiating the
AOT- dentigerous cyst.
 Peripheral variant-gingival fibroma or epulis-growth-labial-palatal
mucosa.
 Slight erosion-alveolar bone-no radiographic change.

13. HISTOPATHOLOGIC FEATURES:
 Spindle shaped epithelial cells - sheets, strands, or whorled
masses of cells in a scant fibrous stroma.
 Epithelial cells- rosette like structures
 Central space- empty or contain small amounts of eosinophilic
material-may stain for amyloid.
 Tubular or duct like structures-characteristic feature-AOT, may
be prominent, scanty, or even absent in a given lesion.
 These consist -central space surrounded-layer of columnar or
cuboidal epithelial cells.
 Nuclei-cells tend-polarized away-central space.
(HE × 160)

14.  Mechanism of formation-tubular structures is not entirely clear
but-result-secretory activity-tumor cells, which appear to be
preameloblasts.
 These structures-not true ducts & no glandular elements are
present-tumor.
 Small foci of calcification-tumor-interpreted as abortive enamel
formation.
 Some AOT-larger areas of calcification-interpreted as dentinoid
or cementum. (HE × 200)

15. Another characteristic cellular pattern-
 Nodules composed-polyhedral, eosinophilic epithelial cells-squamous
appearance-well-defined cell boundaries & prominent intercellular bridges.
 Nuclei may-very mild-pleomorphism.
 Islands may contain pools-amorphous amyloid-like material & globular masses
of calcified substances-Resembles CEOT/AOT lesion
 CEOT like foci-does not influence growth potential of tumor

16.  Yet another epithelial pattern is found between & connecting the cell-
rich nodules & particularly at the tumor periphery.
 Pattern-composed- strands of epithelium, one to two cells in
thickness, forming a trabecular or cribriform configuration.
 Occasional foci-mitotic activity among AOT tumor cells may be
traced, although-not a prominent feature.
 Rare instances melanin pigmentation - both tumor & stroma cells &
presence -melanocytes may be found in AOT’s

17.  Occurrence-hyaline, dysplastic dentinoid material or calcified
osteodentin in AOTs-described -several authors.
 Dentin or dentinoid containing dentinal tubules is exceedingly
rare.
 Stroma-fibrous, mature connective tissue without
ectomesenchymal features,
 Production of dysplastic dentinoid is likely - result of-
metaplastic process
 Calcified material-varying amounts-most lesions.
 Irregular calcified bodies- common-often exhibit-concentric or
Liesegang pattern.

18. IHC
 Classical AOT phenotype is characterized by a cytokeratin (CK) profile
similar-follicular cyst and/or oral or gingival epithelium
+ve
• CK5
• CK17
• CK19
-ve
• CK4
• CK10
• CK13
• CK18

19. Differential diagnosis
 1. Dentigerous cyst
 2. Residual cyst
 3. Lateral periodontal cyst
 4. Calcifying odontogenic cyst
 5. Radicular cyst

20. TREATMENT AND PROGNOSIS:
 AOT -completely benign-because of its capsule, it enucleates
easily-bone.
 Aggressive behavior has not been documented
 Recurrence-Rare

21. CALCIFYING EPITHELIAL ODONTOGENIC TUMOR
(PINDBORG TUMOR)
 Pindborg tumor-1955
 Prior 1955-ameloblastoma unusual type with calcification
 Calcifying ameloblastoma
 Adenoid ameloblastoma
 Cystic complex odontoma

22.  Less than 1% of all odontogenic tumor.
 Tumor arises -dental lamina remnants.
 3rd to 6th decades
 Equal sex predilection.
 Mandible: maxilla ratio 2:1

23. CLINICAL AND RADIOGRAPHIC FEATURES:
 A painless, slow growing swelling
 Margins-lytic defect are often scalloped-well defined.
 20%-ill-defined periphery &
 20% corticated border.
 Entirely radiolucent-but calcified structures of varying size &
density.
 Calcifications are usually scattered within the tumor.
 “Driven-snow” pattern of the calcifications.

24.  Maxillary lesions-epistaxis
-Nasal conjesion &
-Headache.
 Short duration-calcifications absent
 Peripheral lesions-D/D-fibrous hyperplasia
-peripheral giant cell granuloma
- epulis
 Surgical removal-peripheral varient- saucerization seen

25. Pathogenesis
 Pindborg-Initially-REE
 Later-chaudhry et.al-incase-REE-without impacted &peripheral
varient-source-other than REE.
 Source-Ramnents of dental lamina.

26. Macroscopy
 Size1-4cms
 Yellow to tan pink or geryish white
 Bisecting-calcified particles-crunching sound

27. HISTOPATHOLOGIC FEATURES:
 CEOT-islands, strands, or sheets of polyhedral epithelial cells in
a fibrous stroma.
 Nuclei-considerable variation & giant nuclei.
 Some tumors -nuclear pleomorphism-feature- not considered-
indicate malignancy.
 Large areas-amorphous, eosinophilic, hyalinised (amyloid-like)
extracellular material

28.  Tumor islands frequently enclose masses-hyaline material-results-
cribriform appearance.
 Calcifications-distinctive feature develop-amyloid-like material &
form concentric rings (liesegang ring calcifications).
 Tend to fuse & form large-complex masses.

29.  Cementum like components of CEOT stroma.
 El-Labban.et.al- Typical banded calcified collegen-cemental sharpey
fibers.
 Amyloid-stimulate-stroma cells-differentiate-collagenous matrix-
minerlize-resembles cementum.

30. Yamaguchi.et.al-
 Clear tumor cells-cytodifferentation-rather than-
degenerative phenomenon.
Occurrence of clear cells

31. Occurrence of Langerhans cells in CEOT
 Asano et al & takata et al-another histologic variant of the
intraosseous CEOT -two japanese patients
 In both cases the tumor chiefly consisted of scattered small islands
of epithelial cells.
 Occasionally several, clear cells positive s-100 protein, iysozome,mt1,
ln-3, and okt6 antibodies, but not for keratin antibody.
 Ultrastructurally,s-100-positive cells-identified -langerhans cells
based-rod & tennis racket- shaped birbeck granules.
 Some correlation b/n tumor regression & number of langerhans cells.
 Langerhans cells in ceots may play a role either in antigen
presentation or in regression of the tumor.

32. Occurrence of myoepithelial cells in CEOT
 Ultrastructural findings-CEOT disclosed-two cell populatlons.
 One population-classic polyhedral epithelial cells, & other
comprised cells arranged peripherally with elongated profiles &
juxtaposed to tumor epithelial cells.
 Latter cells-large number-cytoplasmic fine filaments-similar-
smooth muscle- type cell.
 They showed-lamina densa continuous-neighboring epithelial cells
& demonstrated-large number-hemidesmosomes.

33.  However, desmosomes b/n these cells & tumor epithelial
cells were not present.
 ultrastructural characteristics-cells-interpreted-
myoepithelial cells.
 cell type-found-tumors-glandular origin, has not been
described previously-odontogenic tumors & its occurrence-
CEOT has not been confirmed-other electron microscopic
studies.

34.  Amyloid-like material-Pindborg tumor-investigated by histochemical,
immunohistochemical, biochemical methods & electron microscopy.
 Material generally stains as amyloid (+ve-Congo red or thioflavine T).
 After Congo red staining, the amyloid will exhibit apple-green
birefringence when viewed with polarized light.

35. Differential diagnosis
 Calcifying odontogenic cyst
 Adenomatoid odontogenic tumor,
 Ameloblastic fibroodontoma,
 Ossifying fibroma,
 Osteoblasloma.

36. TREATMENT & PROGNOSIS:
 CEOT-same biologic behavior-ameloblastoma.
 Conservative local resection -include a narrow rim of surrounding bone.
 Recurrence rate -15%.
 Tumors treated - curettage -highest frequency of recurrence.
 Overall prognosis -good.

37. ODONTOGENIC MYXOMA
 Myxomas -arise -odontogenic ectomesenchyme.
 Close microscopic resemblance - mesenchymal portion-developing tooth.
 Soft tissue myxomas -Rare
 Intraosseous counterparts- frequently found
 Very few intraosseous myxomas -other than the jaws, clavicle, ribs, femur
 Intraosseous myxomas are most commonly- jaws & odontogenic in origin.

38. CLINICAL AND RADIOGRAPHIC FEATURES:
 Myxomas -25 to 30 years.
 No sex predilection.
 Mandible -more commonly than maxilla.
 Smaller asymptomatic & discovered -radiographic examination.
 Larger lesions -painless expansion -involved bone.
 Some instances-growth – tumor – rapid

39.  Radiographically, unilocular or multilocular radiolucency-displace or
cause resorption-teeth.
 Radiolucency - irregular or scalloped, fine trabeculae, some
intersecting at right angles- ‘tennis-racquet’ or ‘step-ladder’.
 Large myxomas –mandible- “soap bubble” radiolucent pattern-
indistinguishable from-ameloblastomas.

40. Zhang et al., classified radiographic appearances of OM
into six types:
 Type I: Unilocular well-defined radiolucency,
 Type II (multilocular): Two or more compartments with multiple
interlaced osseous trabeculae described as honey comb, soap bubble
or tennis racquet radiolucency,
 Type III: Lesion located in alveolar bone,
 Type IV: Lesion involving the maxillary sinus,
 Type V (moth eaten appearance): Larger radiolucent area with
irregular borders,
 Type VI: Combination of bone destruction and bone formation giving
sun ray appearance.

41. Pathogenesis
“According to Lucas“-OM-odontogenic tumor-frequent-adolescence-
association-missing or unerupted teeth-sporadic presence of odontogenic
epithelium.
Adekeye et at" reviewed-different arguments-individual tissues-considered-
possible sources of OMs-dental papilla, dental follicle, & periodontal tissues-
as possible "germ centers“
No strong evidence-odontogenic origin could be found except-OM’s -
degenerative form of odontogenic fibroma-Intraosseous neurofibroma, showing
extensive myxomatous changes, would have a number of features in common
OM

42.  Lombardi et al-not find similar staining patterns for vimentin &
S-100 protein-OMs compared to dental follicle, dental papilla,&
periodontal ligament cells-
 suggesting nonodontogenic origin for the tumor.
 Other studies suggested that-
Myofibroblastic origin or
Dual fibroblastic-histiocytic origin.

43. HISTOPATHOLOGIC FEATURES:
Haphazardly arranged stellate, spindle shaped, & round cells in an
abundant, loose mucoid stroma that contains only a few collagen
fibrils.
H and E ×10)

44.  Histochemical study shows-ground substance –composed-
glycosaminoglycans, chiefly hyaluronic acid & chondroitin sulfate.
 Immunoreactivity-antibodies directed against vimentin
 Focal reactivity- muscle-specific actin.
 Immunohistochemically-myxoma cells show diffuse of inactive-appearing
odontogenic epithelial rests maybe scattered throughout the myxoid ground
substance.
(H and E ×40)

45.  Epithelial rests are not required-diagnosis & not obvious -most
cases.
 Some patients-tumor may-greater tendency-form collagen
fibers-designated as fibromyxomas or myxofibromas.
 Myxoma-microscopically confused- myxoid jaw neoplasms:
-Chondromyxoid fibroma or
-Myxoid neurofibroma.

46. Differential diagnosis
 Ameloblastoma,
 OKC,
 Intraosseous hemangioma,
 Simple cysts,
 Giant cell granuloma.

47. TREATMENT AND PROGNOSIS
 Small myxomas – curettage.
 Reevaluation -at least 5 years.
 Larger lesions, more extensive resection-because-not
encapsulated & tend to infiltrate the surrounding bone.
 Recurrence rate-25%.
 Overall prognosis - good
 Metastases do not occur.

48. Conclusion
AOT & CEOT& ODONTOGENIC MYXOMA are of odontogenic origin,
commonly seen in adolescence & are occasionally associated with
unerupted teeth. Hence through knowledge about these lesions is
necessary for proper diagnosis & treatment plan.

49. References
 Textbook Of Oral & Maxillofacial Pathology: Neville 1st South Asian Edition
 Textbook Of Oral & Maxillofacial Pathology:7th Edition Shafer’s
 Adenomatoid Odontogenic Tumor Of The Mandible: Review Of The Literature And
Report Of A Rare Case :Journal Of Head & Face Medicine 2005, Vol 1:3
 Calcifying Epithelial Odontogenic Tumor (Pindborg Tumor) Head And Neck Pathol
(2011) 5:137–139
 Calcifying Epithelial Odontogenic Tumor :Hindawi Publishing Corporation Journal Of
Case Reports In Pathology Volume 2013
 Adenomatoid Odontogenic Tumor, An Uncommon Tumor: Contemporary Clinical
Dentistry | Apr-jun 2012 | Vol 3| Issue 2
 Odontogenic Myxoma: National Journal Of Maxillofacial Surgery | Vol 4 | Issue 1
| Jan-jun 2013
 Textbook Of Odontogenic Tumors & Allied Lesions: peter.A.Reichart/Hans
P.Philipsen