Benign odontogenic and non odontogenic tumours

Benign odontogenic and non odontogenic tumours

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2. Benign Odontogenic and Non-Odontogenic Tumors of the Jaws Abhishek Roy III MDS 2

3. Classification of Benign Odontogenic Tumors I. Odontogenic epithelium without odontogenic ectomesenchyme A. Ameloblastoma B . Calcifying epithelial odontogenic tumor C. Adenomatoid odontogenic tumor II . Odontogenic epithelium with odontogenic ectomesenchyme with or without hard tissue formation A. Ameloblastic fibroma B. Ameloblastic fibro- odontoma C. Compound odontoma D . Complex odontoma III. Odontogenic ectomesenchyme with or without included odontogenic epithelium A. Odontogenic fibroma B. Odontogenic myxoma C . Cementoblastoma 3

4. WHO Classification, 2017 Epithelial Origin – Ameloblastoma Calcifying epithelial odontogenic tumour Adenomatoid odontogenic tumour Mixed Origin – Ameloblastic Fibroma Odontoma Mesenchymal Origin – Odontogenic Myxoma Cementoblastoma Cemento -ossifying fibroma 4

5. Tumors of Odontogenic Epithelium 5

6. Ameloblastoma The ameloblastoma is the most common clinically significant odontogenic tumor . It may develop from C ell rests of the dental lamina Developing enamel organ Epithelial lining of odontogenic cyst Basal cells of oral mucosa 6

7. Ameloblastoma It is typically slow-growing, locally invasive and runs a benign course H.G.B. Robinson described it as being a benign tumor that is “usually unicentric , non-functional, intermittent in growth, anatomically benign and clinically persistent” 7

8. Ameloblastoma Ameloblastomas occur in 3 different clinico -radiographic situations requiring different therapeutic considerations and having different prognoses. Conventional Solid/ Multicystic (86 % of all cases) Unicystic (13 % of all cases) Peripheral or Extraosseous (1 % of all cases) 8

9. Multicystic Ameloblastoma 9

10. Solid or Multicystic Ameloblastoma : Clinical Features Patient Age: Approximately equal frequency from the third through the seventh decades Sex Predilection: Approximately equal Gender Predilection: Approximately equal 10

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12. Solid or Multicystic Ameloblastoma : Radiographic Features Radiolucent lesion which is usually well-circumscribed; it may be unilocular or multilocular (soap-bubble, honeycomb); occasionally an ameloblastoma will be ill-defined with a ragged border 12

13. Solid or Multicystic Ameloblastoma: Histologic Features There are six microscopic subtypes – Follicular Plexiform Acanthomatous Granular Basal Desmoplastic 13

14. Solid or Multicystic Ameloblastoma : Histologic Features The follicular type is composed of islands of epithelium which resemble the enamel organ in a mature fibrous connective tissue stoma. 14

15. Solid or Multicystic Ameloblastoma : Histologic Features The plexiform type is composed of long, anastomosing cords or larger sheets of odontogenic epithelium. Its stroma tends to be loose and more vascular . 15

16. Solid or Multicystic Ameloblastoma : Histologic Features The acanthomatous type shows evidence of extensive squamous metaplasia with keratin formation in the island of odontogenic epithelium. 16

17. Solid or Multicystic Ameloblastoma: Histologic Features In the granular cell type there is transformation of groups of epithelial cells to granular cells; the nature of the granular change is unknown. This type is more common in young patients and has been shown to be clinically aggressive. 17

18. Solid or Multicystic ameloblastoma : Histologic Features The basaloid type is the least common and is composed of uniform basaloid cells with no stellate reticulum . 18

19. Solid or Multicystic Ameloblastoma : Histologic Features The desmoplastic form is composed of islands/cords of odontogenic epithelium in a very dense collagenous stroma . 19

20. Solid or Multicystic Ameloblastoma: Treatment Treatments have ranged from simple enucleation and curettage to en bloc resection. Marginal resection is the most widely used method of treatment with the least recurrences reported (up to 15 %). Most surgeons advocate a margin of at least 1.0 cm beyond the radiographic limits of the tumor as the tumor often extends beyond the apparent radiologic/clinical margins. 20

21. Solid or Multicystic Ameloblastoma : T reatment Treatment with curettage has resulted in recurrence rates ranging from 55-90 %. Ameloblastomas of this type arising in the maxilla are particularly dangerous as it is often difficult in getting adequate margins. Rarely is an ameloblastoma life threatening . 21

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25. Unicystic Ameloblastoma 25

26. Unicystic Ameloblastoma : Clinical Features Patient Age: 50 % that have been reported were during the second decade of life Sex Predilection: Approximately Equal Location: 90 % occur in the mandible usually in the posterior region . 26

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28. Unicystic Ameloblastoma : Radiographic Features Typically appears as a radiolucency around the crown of an unerupted tooth (most commonly a mandibular third molar ) 28

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30. Unicystic Ameloblastoma : Histologic Features Luminal : the tumor is confined to the luminal surface of the cyst. Intraluminal/ plexiform : the tumor projects from the cystic lining; sometimes resembles the plexiform type of solid/ multicystic ameloblastoma . Mural: the tumor infiltrates the fibrous cystic wall 30

31. Unicystic Ameloblastoma: Treatment and Prognosis Enucleation of the cyst is probably adequate for the luminal and intraluminal/ plexiform types Treatment of the mural type is controversial with some surgeons believing that local resection is best 10-20 % recurrence after enucleation and curettage with all unicystic ameloblastomas 31

32. Peripheral Ameloblastoma 32

33. Peripheral Ameloblastoma These tumors are extraosseous and therefore occupy the lamina propria underneath the surface epithelium but outside of the bone. Histologically, these lesions have the same features as the intraosseous forms of the tumor 33

34. Peripheral Ameloblastoma: Clinical Features Patient Age: Wide age range but most occur during middle-age Gender Predilection: Uncertain Location: There is a slight predilection for the mandible. The buccal mucosa has been the site in a few reported cases 34

35. Peripheral Ameloblastoma : Histologic Features Histologic Appearance: Islands of ameloblastic epithelium are observed in the lamina propria ; plexiform and follicular patterns are the most common; in 50 % of the cases the tumor connects with the basal cell layer of the surface epithelium 35

36. Peripheral Ameloblastoma: Treatment and Prognosis Patients respond well to local surgical excision Some reports indicate a 15 % recurrence rate but in these cases as second surgical procedure results in cure 36

37. Calcifying Epithelial Odontogenic Tumour Pindborg Tumour 37

38. Calcifying Epithelial Odontogenic Tumor (CEOT; Pindborg Tumor) Pindborg tumor accounts for < 1 % of all odontogenic tumors Bony lesions most commonly present as painless, slow-growing swellings It is clearly of odontogenic origin but its histogenesis is uncertain The tumor cells are said to resemble cells of the stratum intermedium 38

39. CEOT: Clinical Features Patient Age: Patients ages range from the 2 nd to the 10 th decades with a mean around 40 years Gender Predilection: None Location: 75 % of the CEOTs occur in the mandible with most occurring in the posterior region 39

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41. CEOT: Radiographic Features CEOTs occur as radiolucent lesions with/without opaque foci They are usually well-circumscribed and may be unilocular or multilocular Slightly over 50 % of the CEOTs are associated with an impacted tooth 41

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44. CEOT: Histologic Features This lesion is typically composed of islands, sheets or strands of polyhedral epithelial cells in a fibrous stroma . Areas of amorphous, eosinophilic, hyalinized extracellular material may be scattered throughout. Cells outlines are distinct and intercellular bridges may be seen. Nuclei show considerable variation with giant nuclei and pleomorphism observed. Calcifications may be noted as well as amyloid-like material. Liesegang rings also may be present. 44

45. CEOT: Additional Features, Treatment and Prognosis Conservative local resection is the treatment of choice as these lesions are typically less aggressive than the ameloblastoma . With this treatment the recurrence rate is approximately 15 % and the overall prognosis is good However, larger lesions (>4cm) require marginal resection 45

46. Misra SR, Lenka S, Sahoo SR, Mishra S. Giant Pindborg Tumor (Calcifying Epithelial Odontogenic Tumor ): An Unusual Case Report with Radiologic-Pathologic Correlation. J Clin Imaging Sci 2013;3:S11 46

47. Adenomatoid Odontogenic Tumour 47

48. Adenomatoid Odontogenic Tumor (AOT) Formerly called an adenoameloblastoma , the AOT represents about 3-7 % of all odontogenic tumors. This epithelial tumor has an inductive effect on the odontogenic ectomesenchyme with dentinoid frequently being produced . 48

49. AOT: Clinical Features Patient Age: The peak age is in the second decade with a mean around 17 years Gender Predilection: Females, 2:1 Location: 65% of the AOTs occur in the maxilla with most occurring in the canine region. 75% percent of the cases are associated with the crown of an unerupted tooth 49

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51. AOT: Radiographic Features AOTs typically appear as pericoronal radiolucencies , which may have radiopaque material (“snowflake” calcifications) within the lucency . These lesions are frequently asymptomatic and therefore are discovered upon routine radiographic examination . 51

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53. AOT: Histologic Features The lesion is usually surrounded by a thick, fibrous capsule. The tumor is composed of spindle-shaped epithelial cells that form sheets, strands or whorled masses with little connective tissue. The epithelial cells may form rosette-like structures, tubular or duct-like structures may be prominent or absent. Calcifications may be observed in the tumor mass. 53

54. AOT: Treatment and Prognosis Enucleation is the treatment of choice as the tumor is easily removed from the bone. AOTs seldom recur 54

55. Ameloblastic Fibroma 55

56. Ameloblastic Fibroma: Clinical Features This true mixed odontogenic tumor is more common in patients in the 1 st and 2 nd decades of life with a mean of 14 years. It is slightly more common in males than females Approximately 70 % of the ameloblastic fibromas occur in the posterior mandible 56

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59. Ameloblastic Fibroma: Radiographic Features Generally, these lesions appear as either a unilocular or multilocular radiolucency. They tend to be well-defined and may have a sclerotic border. Approximately, 50 % are associated with an unerupted tooth. 59

60. Ameloblastic Fibroma: Histologic Features The tumor is composed of a cell-rich mesenchymal tissue resembling the primitive dental papilla admixed with proliferating odontogenic epithelium. 60

61. Ameloblastic Fibroma: Additional Features, Treatment and Prognosis The tumor is often encapsulated with small tumors usually being asymptomatic. Larger tumors produce swelling, which can expand the cortex and be quite pronounced. Most ameloblastic fibromas are treated by conservative surgical excision; however, a 20% recurrence rate has led some surgeons to recommend a more aggressive approach in case of larger lesions 61

62. Odontoma 62

63. Odontoma The odontoma is the most common odontogenic tumor It is not a true neoplasm but rather is considered to be a developmental anomaly ( hamartoma ) Two types of odontomas are recognized: Compound: this type of odontoma is composed of multiple small tooth-like structures. Complex: this lesion is composed of a conglomerate mass of enamel and dentin, which bears no anatomic resemblance to a tooth. 63

64. Odontoma: Clinical Features Patient Age: Mostly during the 2 nd decade of life with a mean of 14 years Gender Predilection: Approximately equal Location: The compound type is more often in the anterior maxilla while the complex type occurs more often in the posterior regions of either jaw 64

65. Odontoma: Radiographic Features Early lesions are radiolucent with smooth, well-defined contours. Later a well-defined radiopaque appearance develops. The compound type shows apparent tooth shapes while the complex type appears as a uniform opaque mass with no apparent tooth shapes present. 65

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70. Odontoma: Additional Features Most odontomas are small and do not exceed the size of a normal tooth in the region However, large ones do occur and these may cause expansion of the jaw Most odontomas are asymptomatic and as a result are discovered upon routine radiographic examination 70

71. Odontoma: Histologic Features The compound odontoma is composed of enamel, dentin and cementum arrange in recognizable tooth forms; some enamel matrix may be retained in immature and hypomineralized specimens The complex odontoma is composed of enamel, dentin and cementum but these tissues are arranged in a random manner that bears no morphological resemblance to a tooth 71

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74. Odontoma: Treatment and Prognosis Odontomas are treated by simple local excision and the prognosis is excellent. 74

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76. Odontogenic fibroma 76

77. Odontogenic Fibroma: Clinical Features Patient Age: Patients have ranged in age from 9-80 years old with a mean of 40 years Gender Predilection: Females, 7.4:1 in one study Location: In the maxilla, most are located anterior to the first molar. When in the mandible, approximately 50 % occur in the posterior jaw 77

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81. Odontogenic Fibroma: Radiographic Appearance The odontogenic fibroma usually appears as a well-defined, unilocular radiolucency. It is often associated with the apical area of an erupted tooth Larger lesions are often multilocular Many odontogenic fibromas have sclerotic borders Root resorption is common 81

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84. Odontogenic Fibroma: Additional Features Small odontogenic fibromas are usually asymptomatic The larger lesions may be associated with localized bony expansion of the jaw or with the loosening of adjacent teeth 84

85. Odontogenic Fibroma: Histologic Features The simple odontogenic fibroma is composed of stellate fibroblasts arranged in a whorled pattern with fine collagen fibrils and a lot of ground substance. Foci of odontogenic epithelium may or may not be present. Occasionally, foci of dystrophic calcification may be present. 85

86. Odontogenic Fibroma: Histologic Features The WHO type odontogenic fibroma appears as a fairly cellular fibrous connective tissue with collagen fibers arranged in interlacing bundles. Odontogenic epithelium in the form of long strands or isolated nests is present throughout the lesion. Calcifications composed of cementoid and/or dentinoid may be present. 86

87. Odontogenic Fibroma: Treatment and Prognosis The odontogenic fibroma is usually treated by enucleation and curettage 87

88. Odontogenic Myxoma : Clinical Features Patient Age: 10-50 years with a mean around 30 years Gender Predilection: Reported to be about equal Location: May occur in any area of the jaws but more common in the mandible . 88

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90. Odontogenic Myxoma : Radiographic Features Radiolucent lesion often with a multilocular appearance. The borders may be indistinct. 90

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92. Odontogenic Myxoma: Histologic Features The tumor is composed of loosely arranged stellate, spindle-shaped and round cells in an abundant, loose myxoid stroma with few collagen bundles. Epithelial cells are not required for diagnosis. The odontogenic myxoma may be confused with a chrondromyxoid fibroma or with myxoid change in an enlarged dental follicle or papilla. 92

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94. Odontogenic Myxoma: Treatment and Prognosis Small odontogenic myxomas are treated by curettage, while larger lesions may require surgical resection as they are not encapsulated and tend to infiltrate adjacent tissues Recurrence rates of up to 25 % are reported Overall, the prognosis is good for most odontogenic myxomas 94

95. Non Odontogenic Tumours 95

96. Classification Fibro-osseous lesions – Ossifying fibroma Langerhans cell disease Lesions containing multinucleated giant cells Neurogemic Tumours – Schwannoma Neurofibroma Bone tumours – Osteoma Chondroma 96

97. Ossifying fibroma 97

98. Ossifying Fibroma – Clinical Features Benign neoplasm characterised by the replacement of normal bone by fibrous tissue and varying amounts of newly formed bone or cementum like material P resents as painless, slow growing expansile lesion Occurs mostly in 3 rd and 4 th decade of life More frequently in females Preferred area is the mandible molar – premolar region 98

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100. Ossifying Fibroma – Radiographic Features Well defined radiolucency with varying degrees of calcification. Borders may be sclerotic 100

101. Ossifying Fibroma – Treatment and Prognosis Surgical excision for smaller lesions and marginal mandibulectomy and segmental resection for bigger tumours 101

102. Langerhans cell disease 102

103. Langerhans Cell Disease– Clinical Features Proliferation of Langerhans cells accompanied by varying number of eosinophils, other chronic inflammatory cells and multinucleated giant cells They present as solitary or multiple lesions in bone. They can cause pain and tenderness, tooth mobility and bony expansion 103

104. Langerhans Cell Disease– Clinical Subtypes Chronic Localised – Eosinophilic granuloma Acute disseminated Langerhans cell disease – Letterer Siwe disease Chronic disseminated Langerhans cell disease – Hand- Schuller -Christian disease 104

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106. Langerhans Cell Disease– Radiographic Features Well defined punched out radiolucencies , sometimes will be ill defined, which cause floating tooth appearance 106

107. Langerhans Cell Disease– Treatment and Prognosis Aggressive local curettage and resection with minimum 5mm safety margins, depending on size Chemotherapy and radiotherapy have also produced varying degrees of success 107

108. Central Giant Cell Granuloma 108

109. Central Giant Cell Granuloma– Clinical Features Age: Average of 30 years Female gender is more preferred Occurs more in mandible, anterior t o 1 st molar and frequently crosses midline 109

110. Central Giant Cell Granuloma– Clinical Features Presents as a painless growth, which has good chances to become secondarily infected 110

111. Central Giant Cell Granuloma– Radiographic Features Unilocular or multilocular radiolucency that is well delineated 111

112. Central Giant Cell Granuloma– Histological Features Benign proliferation of fibroblasts and multinucleated giant cells 112

113. Central Giant Cell Granuloma– Treatment and Prognosis Surgical curettage with a average recurrence of 15-20% Various non surgical injections – triamcinolone, calcitonin, α -Interferon have been tried but all of them still require surgical intervention 113

114. Schwannoma 114

115. Schwannoma – Clinical Features Benign tumour of neurilemma or nerve sheath If in bone, exists as a well defined radiolucency 115

116. Schwannoma – Histological Features Well encapsulated and predominantly have spindle cells 116

117. Schwannoma – Treatment Surgical excision with no recurrence 117

118. Osteoma 118

119. Osteoma– Clinical Features Benign tumour of mature compact or cancellous bone May arise on surface of bone (periosteal osteoma) or centrally within the bone (endosteal osteoma) Most common during 2 nd – 5 th decade with definite male predilection In face, posterior mandible is most preferred region 119

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121. Osteoma– Radiographic Features Well circumscribed sclerotic radiopaque masses 121

122. Osteoma– Histologic Features and Treatment Dense compact bone with narrow marrow spaces or lamellar trabaculae of cancellous bone with fibrofatty marrow spaces Treatment is surgical excision 122

123. References Shafer’s Textbook on oral pathology Peterson’s Principles of oral and maxillofacial surgery Maxillofacial surgery – Peter Ward Booth 123

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