Odontogenic Tumors Oral Pathology

REVIEW OF ODONTOGENESIS
EPITHELIAL ODONTOGENIC
TUMORS
Ameloblastoma
Common Ameloblastoma
Unicystic Ameloblastoma
Peripheral Ameloblastoma
Calcifying Epithelial Odontogenic Tumor
Adenomatoid Odontogenic Tumor
Calcifying Odontogenic Cyst
Squamous Odontogenic Tumor
CONNECTIVE TISSUE ODONTOGENIC
TUMORS
Odontogenic Fibroma
Peripheral Odontogenic Fibroma
Central Odontogenic Fibroma
Odontogenic Myxoma
Cementoblastoma
MIXED ODONTOGENIC TUMORS
Ameloblastic Fibroma
Odontoma
Ameloblastic Fibro-Odontoma
MALIGNANT ODONTOGENIC
TUMORS
Malignant Ameloblastoma
Ameloblastic Carcinoma
Odontogenic Carcinoma
Primary Intraosseous Carcinoma

1. ODONTOGENIC TUMORS Sana Rasheed ODONTOGENIC TUMORS Sana Rasheed Akhtar Saeed Medical and Dental College, Lahore, Pakistan

2. EPITHELIAL ODONTOGENIC TUMORS

3. AMELOBLASTOMA A locally aggressive neoplasm of odontogenic epithelium that has a wide spectrum of histologic patterns resembling early odontogenesis . It is a benign neoplasm . Four sources: (1 ) remnants of the dental lamina (rests of Serres ) ( 2) reduced enamel epithelium (3) rests of Malassez ( 4) the basal cell layer of overlying surface epithelium

4. Common features: Slow growing Locally aggressive Capable of causing large facial deformities A high recurrence rate Metastasis is rare

5. Common Ameloblastoma CONVENTIONAL SOLID OR MULTICYSTIC INTRAOSSEOUS AMELOBLASTOMA Other names: simple or follicular ameloblastoma occur in patients over 25 years of age third to seventh decades of life (25+ to 60s) CLINICAL FEATURES May produce extensive, even grotesque, deformities of the mandible and maxilla . Often asymptomatic , painless, bony expansion. Painless and no paresthesia. It is most commonly located in the mandible , with 75% occurring in the molar and ascending ramus areas. Lesions of the maxilla are located in the molar area and may extend to the maxillary sinus and floor of the nose. Age: patients between 20 to 40 years of age . No significant sex or race predilection exists.

6. Tendency to expand the bony cortices. T hinned outer shell of bone cracks easily when palpated—a diagnostic sign referred to as “ eggshell cracking .” RADIOGRAPHIC FEATURES Multilocular lesions are described as having a “ soap bubble ” appearance (when the radiolucent loculations are large ) or as being “ honeycombed ” (when the loculations are small )

7. HISTOPATHOLOGY Reverse polarization in basal cell layer in the epithelium The cytoplasm adjacent to the basement membrane assumes a clear zone . DD: calcifying odontogenic cysts and odontogenic keratocysts . Specific architectural patterns of epithelium: two most common are the follicular and plexiform patterns

8. The follicular pattern Most prevalent It consists of epithelium in the form of islands, strands, and medullary arrangements. B ackground stroma of fibrous connective tissue . The epithelial arrangements: O uter border : the palisaded ameloblast -like cells in which reversed polarization has occurred. Inside: loosely arranged and widely separated triangular-shaped cells that are similar to those of the stellate reticulum. 5. A distinctive zone of hyalinization surrounds the epithelial islands

9. Acanthomatous pattern : the central cells are transformed to squamous cells that produce keratin within individual cells or in the form of keratin pearls. Granular cell variant : The central cells appear swollen and densely packed with eosinophilic granules

10. Basal cell variant Only densely packed, large proliferating cuboidal-shaped basaloid cells exist in narrow strands Without stellate reticulum or other forms of centrally located epithelial cells

11. Desmoplastic ameloblastoma The epithelial islands and strands are small and have cuboidal and darkly stained cells . The epithelial component is widely separated by fibrous tissue that is dense and scarlike . S mall islands and cords of odontogenic epithelium in a densely collagenized stroma . A particular predilection for penetrating the surrounding trabecular bone and remaining undetected. (metaplastic potential)

12. Desmoplastic ameloblastoma This variant has a mixed radiolucent and radiopaque radiographic appearance that resembles a fibro-osseous lesion. Why is it more difficult to treat? It appears to have a particular predilection for penetrating the surrounding trabecular bone and remaining undetected . Consequently, finding the exact interface of the lesion with normal bone is especially difficult during surgical management .

13. The plexiform pattern E pithelium in a fishnet or mesh arrangement with columnar or cuboidal ameloblast -like cells No reversed polarization of the nucleus in basal cells. General pattern : thin anastomosing strands of odontogenic epithelium. Large and small cystlike areas are present in the connective tissue (as compared to epithelial islands in follicular pattern).

14. Unicystic Ameloblastoma CLINICAL FEATURES Age: 16 to 20 years of age The unicystic ameloblastoma occurs in a dentigerous cyst relationship U sually associated with a severely displaced third molar . Mandible > Maxilla. RADIOGRAPHIC FEATURES Unilocular lesions W ell demarcated C orticated . A tooth is often present within the radiolucency. Root displacement in premolar area.

15. HISTOPATHOLOGY F ibrous connective tissue capsule. A solitary large fluid-filled lumen . The epithelial lining of the lumen : Pallisaded basal cells Hyperchromatic Reverse polarization of nucleus 4. The remaining layers resemble stellate reticulum. Intraluminal unicystic ameloblastoma Epithelium is thickened in some areas with papillary projections extending into the lumen . Mural unicystic ameloblastoma When the thickened lining penetrates the adjacent capsule. Plexiform unicystic ameloblastoma I ntraluminal nodular projections that contain a network or mesh pattern of epithelium.

16. Peripheral Ameloblastoma Limited to the soft tissues of the gingiva . Arises directly from the overlying epithelium or from the remnants of the dental lamina located in the extraosseous soft tissue. DDs: odontogenic hamartoma peripheral odontogenic fibroma

17. CLINICAL FEATURES Age: 23 to 82 years of age Mandible > Maxilla Appear as firm sessile nodules of the gingiva Size : 0.5 to 2.0 cm. They have a smooth surface and normal coloration. May be erythematous or ulcerated. RADIOGRAPHIC FEATURES Lesions are primarily extraosseous . A superficial saucerization of the cortical plate that appears as a cup-shaped radiolucency beneath the elevated nodule as the result of the pressure the lesion exerts on the bone . Tooth separation.

18. HISTOPATHOLOGY I slands and strands of odontogenic epithelium. Acanthomatous pattern common: central areas of keratin formation or the cystic pattern . The epithelial islands and strands are usually surrounded by fibrous tissue . A cup-shaped resorption of the cortical plate.

19. CALCIFYING EPITHELIAL ODONTOGENIC TUMOR A locally aggressive tumor consisting of strands and medullary patterns of squamous and clear cells that are often accompanied by spherical calcifications and amyloid-staining hyaline deposits .

20. CALCIFYING EPITHELIAL ODONTOGENIC TUMOR Other name : “ Pindborg tumor.” L ocally aggressive Origin : It is thought to originate from the epithelial rests of the dental lamina or from the reduced enamel epithelium that overlies the crowns of the teeth it usually contains spherical and diffuse calcifications within the epithelial islands and the connective tissue stroma. CEOT occurs as either a central (intraosseous) or peripheral ( extraosseous ) lesion

21. CALCIFYING EPITHELIAL ODONTOGENIC TUMOR CLINICAL FEATURES

22. CALCIFYING EPITHELIAL ODONTOGENIC TUMOR RADIOGRAPHIC FEATURES A diffuse radiolucency with faint flecks of calcified structures.

23. CALCIFYING EPITHELIAL ODONTOGENIC TUMOR A mixture of radiolucent and radiopaque areas. The radiopaque areas can be diffuse and faint or discrete, round structures . Intraosseous lesions may occur over teeth that are unerupted , displaced, or both . Small lesions are often unilocular radiolucencies . Lesions have indistinct lines of demarcation with the surrounding bone.

24. CALCIFYING EPITHELIAL ODONTOGENIC TUMOR Because CEOT usually occurs over unerupted teeth and may be a radiolucent or mixed unilocular lesion , the radiographic differential diagnosis of CEOT includes dentigerous cyst adenomatoid odontogenic tumor ameloblastic fibro- odontoma The peripheral lesions are commonly radiolucent. Sometimes lesions exhibit superficial cortical erosion.

25. HISTOPATHOLOGY Sheets of polyhedral cells with prominent intercellular bridges . Stains positive with Congo red stain and thioflavine T, shows positivity for * amyloid deposits (it give apple green bifringence ) it can also be positive for *tissue degeneration, *type IV collagen and *basal lamina, *enamel matrix, or *keratin Multiple concentric Liesegang ring calcifications seen. The cells may exhibit pleomorphism multinucleation prominent nucleoli hyperchromatism

26. P ools of homogeneous eosinophilic material are often found within and between the sheets of epithelial cells Scattered spherical calcifications. When clear cells dominate the epithelial component , the lesion is referred to as clear cell variant of CEOT.

27. ADENOMATOID ODONTOGENIC TUMOR Clinical location around the crown of a tooth Lesion probably originates from the reduced enamel epithelium . Lesion is biologically nonaggressive and requires conservative treatment A wellcircumscribed lesion derived from odontogenic epithelium that usually occurs around the crowns of unerupted anterior teeth of young patients and consists of epithelium in swirls and ductal patterns interspersed with spherical calcifications.

28. CLINICAL FEATURES The AOT is usually associated with an impacted tooth and is often a cause of failure of the tooth to erupt. Age: the second decade of life, 14 to 15 years of age. Gender: Females > Men Location: A nterior mouth , usually around an impacted cuspid . Appearance: A n area of swelling over an unerupted tooth. DD: dentigerous cyst unicystic ameloblastoma , CEOT calcifying odontogenic   cyst

29. RADIOGRAPHIC FEATURES A unilocular lesion with well-corticated borders that contains a tooth . Radiolucent lesions, but some contain faint flecks of radiopacities . Lesions often surround the crown of an impacted tooth, as they do in a dentigerous cyst. However , close examination reveals that AOT differs from a dentigerous cyst, because the radiolucency usually extends apically beyond the cemento -enamel junction.

30. HISTOPATHOLOGY O uter capsule of fibrous connective tissue A nodular pattern of epithelial cells . S olid or contain focal cystic areas. The nodules are composed of spindled epithelial cells that are often in a swirled pattern . Distinctive feature of AOT : Ductal epithelial structures composed of a circular arrangement of columnar cells with periodic acid-Schiff (PAS )-positive eosinophilic material. Hyaline rings. Spherical calcifications D iffuse areas of hyaline material in the stroma

31. CALCIFYING ODONTOGENIC CYST ( Gorlin cyst) A rare, wellcircumscribed , solid or cystic lesion derived from odontogenic epithelium that microscopically resembles ameloblastoma but differs by containing ghost cells and spherical calcifications. Also called odontogenic ghost cell tumor

32. CLINICAL FEATURES

33. RADIOGRAPHIC FEATURES W ell-circumscribed U nilocular radiolucencies F lecks of indistinct radiopacities . In some lesions the flecks and small nodular radiopacities are confined to the periphery, with larger toothlike structures more centrally located

34. HISTOPATHOLOGY Some lesions have a cystic center, and others are solid. The epithelial component consists of an outer layer of palisaded columnar basal cells and an inner layer of stellate reticulum like cells. Greatly enlarged eosinophilic epithelial cells without visible nuclei, referred to as ghost cells , are present within the stellate reticulum-like areas . Multiple spherical and diffuse calcifications within the epithelium and connective tissue are also included

35. SQUAMOUS ODONTOGENIC TUMOR A rare, sometimes multifocal , potentially aggressive lesion derived from odontogenic epithelium and consisting of islands of stratified squamous epithelium that commonly contain microcysts and calcifications in a dense fibrous background.

36. SQUAMOUS ODONTOGENIC TUMOR

37. SQUAMOUS ODONTOGENIC TUMOR SOT may originate from the remnants of the dental lamina, rests of Malassez , or overlying epithelium

38. CLINICAL FEATURES

39. RADIOGRAPHIC FEATURES Resorption of roots is usually absent. Tooth separation is common with smaller lesions when they are located in the bone that is coronal to the root apices. Large ones are multilocular and have an indistinct border. Small lesions appear as unilocular radiolucencies .

40. HISTOPATHOLOGY

41. CONNECTIVE TISSUE ODONTOGENIC TUMORS

42. ODONTOGENIC FIBROMA A peripheral or intraosseous (central) benign neoplasm derived from connective tissue of odontogenic origin containing widely scattered islands and strands of embryonic odontogenic epithelium and calcifications.

43. Peripheral Odontogenic Fibroma

44. The peripheral odontogenic fibroma is the most common form of odontogenic fibroma and appears to be derived from the overlying gingival epithelium or the rests of the dental lamina remaining in an extraosseous location DDs: gingival hamartoma or a peripheral ameloblastoma

45. Appearance as a focal growth. It may be of normal coloration or erythematous when ulceration occurs. Interdental lesions often cause tooth separation. When lesions contain numerous calcifications within the cellular connective tissue, some small radiopaque flecks may be visible . saucerization of the cortical bone some widening of the cervical portion of the periodontal space. Dense connective tissue that separates localized zones of myxomatous or loose connective tissue. Small epithelial islands Irregularly shaped hyalinized deposits The epithelial islands will often contain clear cells. CLINICAL FEATURES RADIOGRAPHIC FEATURES HISTOPATHOLOGY

46. Central Odontogenic Fibroma CLINICAL FEATURES Asymptomatic Painless swelling Located in mandible. RADIOGRAPHIC FEATURES Unilocular radiolucency W ell circumscribed in some and multilocular in others. Some faint radiopaque flecks HISTOPATHOLOGY a cellular connective tissue that contains widely scattered thin strands of odontogenic epithelium. The epithelial component closely resembles dental lamina and often contains cells with clear cytoplasm. Spherical and diffuse calcifications

47. ODONTOGENIC MYXOMA An aggressive intraosseous lesion derived from odontogenic connective tissue and primarily consisting of a mucoid ground substance with widely scattered undifferentiated spindled mesenchymal cells . CLINICAL FEATURES Mandible = Maxilla Maxillary lesions erode into the sinus, often crossing the midline and into the opposing sinus cavity. Mandibular lesions are most commonly found in the molar and premolar areas and often extend into the ramus. P ainless , slowly enlarging swellings. Displacement of teeth

48. RADIOGRAPHIC FEATURES A multilocular radiolucency with a “soap bubble” or “honeycomb” pattern. Faint residual fragments of trabecular bone Expansion of cortical plates Some tooth displacement occurs.

49. HISTOPATHOLOGY W idely separated spindle- or angular shaped cells against a background of a mucoid, nonfibrillar ground substance . In some odontogenic myxomas , focal areas of fine strands of collagen and blood vessels exhibiting a thin outer zone of hyalinization are found. I slands of residual bone in the periphery. Islands of odontogenic epithelium and focal calcifications. L arge amounts of a mature cellular fibrous tissue . These lesions are referred to as myxofibroma .

50. CEMENTOBLASTOMA A benign, well-circumscribed neoplasm of cementum-like tissue growing in continuity with the apical cemental layer of a molar or premolar that produces expansion of cortical plates and pain . CLINICAL FEATURES Second and third decades of life M olar and premolar area, with lesions attached to the apical third of one of the roots. T rue neoplasms Buccal and lingual cortical plate expansion. Pain is produced. The teeth usually remain vital. RADIOGRAPHIC FEATURES Lesions are unilocular and well demarcated. They may be completely radiolucent, a mixture of radiolucent and radiopaque, or completely radiopaque. Root resorption seen.

51. HISTOPATHOLOGY U nmineralized eosinophilic matrix rimmed by plump cementoblasts . Acellular peripheral zone The Cellular central zone : mineralized tissue multinucleated cells increased number of reversal lines (due to remodeling)

52. MIXED ODONTOGENIC TUMORS

53. AMELOBLASTIC FIBROMA A circumscribed lesion predominantly located over unerupted molars in young patients ; the epithelium and connective tissue recapitulate the cap and bell stages of odontogenesis . CLINICAL FEATURES Y oung patients with an average age of 14 years . It is slow growing Mandibular molar area, often over an unerupted tooth. Slight buccal and lingual cortical expansion. RADIOGRAPHIC FEATURES Lesions are most often over an unerupted tooth. They are unilocular or multilocular radiolucencies . They are well corticated and vary considerably in size.

54. HISTOPATHOLOGY T hin strands and cords of odontogenic epithelium that resembles the dental lamina. The background is composed of embryonic connective tissue containing fibroblasts. Zones of hyalinization , sometimes with associated focal areas of calcification , are often found surrounding the epithelial component of the lesion

55. ODONTOMA Odontomas are composed of mature enamel, dentin, and pulp M ay be compound or complex . Because most occur during the period of normal tooth development and often reach a fixed size, they are not considered true neoplasms, but hamartomas. A usually hamartomatous lesion commonly found over unerupted teeth and containing enamel, dentin, pulp, and cementum in either recognizable tooth shapes (compound) or a solid, gnarled mass (complex).

56. CLINICAL FEATURES 70% of all odontogenic tumors . First and second decades Maxilla > Mandible Tooth fails to erupt at its scheduled time Asymptomatic swelling around the tooth.

57. RADIOGRAPHIC FEATURES Compound odontomas are usually located in the anterior part of the mouth , either over the crowns of unerupted teeth or between the roots of erupted ones. Lesions are usually unilocular , containing multiple radiopaque structures that resemble miniature teeth. Compound odontomas may contain as few as 2 to 3 miniature toothlike structures or as many as 20 to 30. A complex odontoma is most commonly found in the posterior parts of the mandible over impacted teeth and can attain sizes up to several centimeters . They appear as a solid radiopaque mass exhibiting some nodularity and are surrounded by a thin, radiolucent zone . The lesions are unilocular and separated from normal bone by a distinct line of cortication. Individual toothlike structures are absent.

58. HISTOPATHOLOGY The enamel, dentin, and pulpal tissue of the toothlike structures of compound odontoma are arranged in an orderly pattern . Within the surrounding capsule, a thin band of follicular connective tissue separates each miniature conical tooth. Complex odontoma differs by being composed of a single, gnarled, disorganized mass of enamel, dentin, and pulp, with no recognizable tooth shapes. Both compound and complex forms may also contain reduced enamel epithelium, secretory ameloblasts , and functional odontoblasts. Islands of odontogenic rests and spherical calcifications are common in the surrounding connective tissue.

59. AMELOBLASTIC FIBRO-ODONTOMA An expansile growth in young patients that contains the soft tissue components of ameloblastic fibroma and the hard tissue components of complex odontoma .

60. CLINICAL FEATURES First and second decades It is primarily located in the posterior areas of the mandible It appears as a slowly developing swelling of the affected portion of the jaw, usually in the area of an unerupted tooth. RADIOGRAPHIC FEATURES Unilocular , well-circumscribed, mixed radiolucent and radiopaque lesion . The opacities are usually diffuse and nodular. Most lesions also contain an impacted tooth.

61. HISTOPATHOLOGY A reas consist of strands and cords of epithelium that resemble dental lamina B ackground of embryonic connective tissue composed of randomly oriented fibroblasts. In adjacent areas, both mature and immature forms of complex odontoma can be found. The lesion may be slightly lobular but is always surrounded by a well-formed capsule .

62. MALIGNANT ODONTOGENIC TUMORS

63. MALIGNANT AMELOBLASTOMA Ameloblastomas in which metastasis has occurred to regional lymph nodes or to other distant sites, the lungs being most common . Recurrance occurs. A lesion with the histopathologic features of common ameloblastoma in which documented metastasis has occurred.

64. AMELOBLASTIC CARCINOMA An aggressive neoplasm of the mandible or maxilla in which the epithelial component exhibits features of ameloblastoma but with notable cytologic malignancy . The ameloblastic carcinoma differs from malignant ameloblastoma in that portions of its epithelial component are composed of cytologically malignant cells, yet the lesion is still readily recognizable as ameloblastoma

65. The ameloblastic carcinoma differs from malignant ameloblastoma in that portions of its epithelial component are composed of cytologically malignant cells, yet the lesion is still readily recognizable as ameloblastoma

66. ODONTOGENIC CARCINOMA The radiographic appearance exhibits a diffuse “honeycomb” radiolucency, a feature that is consistent with an aggressive destructive intraosseous lesion. Islands and strands of clear cells present. The epithelial structures are usually surrounded by zones of myxomatous connective tissue. An aggressive and destructive intraosseous lesion of the mandible or maxilla that consists of poorly differentiated epithelial cells and clear cells in a pattern that is reminiscent of early odontogenesis . The usual features of malignancy, such as high mitotic index, hyperchromatism , and pleomorphism , are not usually found in these lesions. Odontogenic carcinoma is difficult to cure because it is very infiltrative and has a high rate of recurrence.

67. Honey comb or Soap bubble appearance Common Ameloblastoma Odontogenic myxoma Odontogenic carcinoma (honeycomb)

68. References Contemporary Oral and Maxillofacial Pathology - 2nd Edition Neville Oral and Maxillofacial Pathology Hack Dentistry – Youtube www.pathpedia.com