Tumor of oral cavity

Includes most common tumors of oral cavity including scc,bcc, melanoma, ameloblastoma, odontoma, fibromas, pindborg tumors etc.
Presented by Dr. Binaya Subedi

1. Tumors of Oral Cavity Binaya Subedi BDS Intern School Of Dental Sciences, CMC

2. Definition Classification of tumors of oral cavity Tumors of Epithelial origin Benign Malignant Tumors of Connective Tissue Origin Odontogenic Tumors Contents

3. Tumor: “a swelling of the tissue.” Neoplasia : “An abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of the normal tissues and persists in the same excessive manner after cessation of the stimuli, which evoked that change.” -Robin’s Basic Pathology (10 th etd .) Introduction

4. According to GLOBOCAN 2012, lip and  oral cavity cancer  is the 12th most common  cancer  in  Asia  and ranks 8th among all the  cancers  in men. Second most common cancer in men in south east asia . Introduction

5. Classification Based on Tissue of origin; Non- Odontogenic Tumors Tumors of Epithelial tissue origin Tumors of Connective tissue origin Tumors of Salivary gland origin Tumors of Muscle tissue origin Tumors of Nerve tissue origin Metastatic tumors of jaws Odontogenic Tumors Based on differentiations Benign tumors Malignant tumors

6. WHO Histologic Classification of Tumors of Oral cavity, 2017

7. Benign Tumors of Epithelial Origin

8. Squamous Papilloma A ssociated with papilloma virus HPV 6 & 11, non-contagious. Virus-induced focal papillary hyperplasia of the mucosa, similar to verruca vulgaris. A n exophytic , pedunculated , painless growth made up of numerous , small finger-like projections, which result in a lesion with a roughened, verrucous or ‘cauliflower’ surface . F ound most commonly on the tongue, lips, buccal mucosa, gingiva & palate, esp. that area adjacent to the uvula.

9. Treatment: Excision, including the base of the mucosa into which the pedicle inserts. If properly excised, recurrence is very rare. O ther methods; conservative surgical excision curettage liquid nitrogen cryotherapy topical keratolytic agents (usually containing salicylic acid and lactic acid)

10. L ow-grade malignancy that originates in the pilosebaceous glands which is considered to be a variant of invasive squamous cell carcinoma. Sunlight, trauma, HPV, Chemical Carcinogens are common etiological factors in genetically susceptible and immuno -compromised host. More common in fair-skinned people and in sun-exposed areas Keratoacanthoma (self healing carcinoma, molluscum sebaceum , verrucoma )

11. Occurs in all age groups but incidence increases with age. Men : women = 2:1 Face , neck and dorsum of upper extremities are the most common sites. Intraoral lesions are quite uncommon. May be seen on lips . Lesions are typically solitary elevated, umbilicated or crateriform with a depressed central core or plug. Its often painful and regional lymphadenopathy may be present. Treatment: Surgical excision

12. Hamartomas , i.e . benign proliferations of nevus cells in either epithelium or CT Can be congenital or acquired Histologically, Intradermal Junctional Mucosal Most common mucosal type is the intramucosal nevus, followed by the common B lue nevus. Oral Nevi O ral melanocytic nevus, nevocellular nevus, mole

13. Usually occurs in White patients over 40 years, mostly female on hard palate and buccal mucosa. Asymptomatic, pigmented, brown black or blue colored, well circumscribed, raised lesions. Sometimes amelanotic , sessile growths which resemble fibromas or papillomas . Compound nevus; involving mucosal epithelium and CT

14. White sponge nevus   a condition characterized by the formation of white  patches that appear as thickened, velvety , sponge-like tissue. most commonly found on the buccal mucosa Treatment of oral nevus: Surgical excision Congenital nevi have a greater risk for malignant transformation .

15. Malignant Tumors of Epithelial Origin

16. S low growing, rarely metastasizes but has ability to produce significant local destruction . Most frequently develops on the exposed surfaces of the skin, face and scalp in middle aged or elderly fair skinned persons. It is thought to arise from pluripotent stem cells of the basal cell layer as well as follicular structures. Basal Cell Carcinoma Rodent Ulcer

17. Etiology: UV light (chronic sun ray exposure)– most important and common cause Radiation like X-rays Chemicals like arsenic Immunosuppression Syndromes like Xeroderma Pigmentosum and N evoid BCC syndrome

18. Clinical features : • Most frequently in the fourth decade of life • Male :female =2:1 • Most frequently seen on the middle third of face • Does not arise from the oral mucosa so is not seen intraorally except for invasion from an adjacent skin surface. Subtypes of BCC; Nodular BCC Pigmented BCC Cystic BCC Superficial BCC Morpheaform and infiltrating BCC

19. A. Nodular BCC: M ost common variety. It begins as a slightly elevated papule with a central depression which ulcerates, heals over and then breaks down again. Very mild trauma may cause bleeding. Eventually , the crusting ulcer which appears superficial develops a smooth, rolled border representing tumor cells spreading laterally beneath the skin . B. Pigmented BCC I n addition to the features seen in the nodular type, this type contains black or brown pigmentation and are seen more commonly in dark skinned people. C. Cystic BCC M ay contain translucent blue-gray cystic nodules that may mimic benign cystic lesions.

20. D. Superficial BCC presents as scaly patches or papules, commonly on the trunk, E. Micronodular BCC An aggressive variety, less prone to ulceration May have a seemingly well-defined border. F. Morpheaform and infiltrating BCC aggressive types with sclerotic (scar-like) plaques or papules, which may be mistaken for scar tissue . Border is usually not well defined and often extends well beyond clinical margins . Ulceration , bleeding and crusting are common.

21. Treatment: Small lesions (<1 cm)– surgical excision, laser ablation or electrodissection and curettage, with 5 mm margins of normal appearing skin. Large lesions – radical surgery or radiation therapy. For sclerosing type or recurrent lesions, M ohs Micrographic surgery should be used. Prognosis is usually good as the tumor doesn’t metastasize and recurrence is rare.

22. M alignant neoplasm of squamous differentiation as characterized by the formation of keratin pearsls and/or the presence of intercellular bridges . The most common malignant neoplasm of the oral cavity . Squamous cell carcinoma ( Epidermoid Carcinoma) Note: Unless specified oral carcinoma always means Squamous cell carcinoma

23. Etiology: Tobacco in its various forms, sespecially when coupled with excess alcohol . High exposure to UV radiation Premalignant lesions and conditions (Leukoplakia) Poor oral hygeine V itamin A and C deficiency I mmunosuppressed Rare conditions like xeroderma pigmentosum HPV infection Besides all the causes, tobacco and UV radiation is only established causes of SCC. All other causes are supposed to have synergistic effects on former two causes.

24. Clinical Features: Male: female = 2:1 Mainly found in the elderly, after the fourth decade of life . Commonly affects vermilion border of lower lip, tongue, floor of mouth, palate, gingiva, buccal mucosa in descending order. The mortality rate is the lowest for lip cancer and highest for the tongue. Clinically, two very characteristic features are ulceration and an indurated margin. Any swellings, papules, discolorations that shows abrupt increase in size, with change in surface texture with surface ulcerations, change in surface colors any chronic non-healing ulcers are all indicative of squamous cell carcinoma. Regional lymph nodes are enlarged and tender, simulating metastatic tumor. Pain and difficulty in mastication are the common complaints

25. Carcinoma of Lips Chiefly occurs in the elderly men , in the lower lip . Clinical features : Usually begins on the vermilion border of the lip to one side of the midline. Often starts as a small area of thickening, induration, and ulceration or irregularity of the surface. Later, it may create a small crater-like defect or produce an exophytic , proliferative growth. Generally, slow to metastasize when does, usually ipsilateral and involves the submental or submandibular nodes . Contra lateral metastasis may occur only if the lesion is near or crosses the midline . Treatment and Prognosis: Surgical excision with or without radiation Prognosis is good.

26. Carcinoma of Tongue A relationship has been suggested between syphilis and tongue carcinoma but nothing has been proved as yet . Clinical features : Develops on the lateral border or ventral surface of the tongue . It presents as a painless mass or ulcer , which might become painful if secondarily infected . May begin as a superficially indurated ulcer with slightly raised borders and may develop into a fungating exophytic mass or infiltrate the deep layers of the tongue, producing fixation and induration. Lesions on the posterior portion are usually of a higher grade of malignancy. Treatment and Prognosis Surgical Excision with radiation (difficult to treat) Poor prognosis

27. Carcinoma of floor of mouth Clinical Features: An indurated ulcer of varying size, situated on one side of the midline . More frequently in the anterior portion of the floor. Sometimes it may produce limitation of motion of the tongue or slurring of speech. Contra lateral metastasis is common as the primary lesion occurs most commonly near the midline, where lymphatic cross-drainage occurs . Treatment and Prognosis: Radiation better than surgery Smaller lesions recur, larger don’t. Fair prognosis

28. Carcinoma of Buccal Mucosa It has a strong predilection of occurrence in men, almost ten times more. Etiology : Habitual quid of chewing tobacco for years . Clinical features : Usually develops along or inferior to a line opposite the plane of occlusion . Lesion is often a painful ulcerative one where induration and infiltration of deeper tissues is common. Some lesions may even be exophytic . Metastasis is very frequent. Treatment : • Combined use of surgery or x-ray radiation.

29. Carcinoma of Gingiva Clinical features : More commonly found in the mandibular gingiva . Initially presents as an area of ulceration, which may be purely erosive or may exhibit an exophytic growth usually arises more commonly in edentulous areas. Attached gingiva is more commonly involved than the free gingiva . Erosion of the underlying bone is frequent. Metastasis is more common from the mandibular gingiva. Treatment : T reatment is generally difficult Bad prognosis

30. Carcinoma of Palate Not a common lesion of the oral cavity. Clinical features : Poorly defined, ulcerated, painful lesion on one side of the midline . It frequently crosses the midline and may extend laterally to include the lingual gingiva or posteriorly to involve the tonsilar pillar or even the uvula . It may invade the bone or occasionally the nasal cavity, while infiltrating lesions of the soft palate may extend into the nasopharynx . Metastasis occurs quite commonly. Treatment : Both surgery and x-ray radiation are used. Prognosis is not very good.

31. TNM Grading Of SCC Proposed by Pierre Denoix 1940s Adopted by International Union Against Cancer (UICC ) in 1968

32. Treatment of Oral SCC Surgery Excisional surgery Cryosurgery Curettage and electrodesiccation ( electrosurgery ) Laser surgery Chemotherapy Radiation therapy Teletherapy Brachytherapy As a thumb rule, Stage I and Stage II cancers  surgery with or without radiotherapy. Stage III  Radiation therapy and surgery with or without chemotherapy Stage IV cancers  Supportive care

33. Radiation dose: A dose between 50 and 70 Gy , usually given over a 5- to 7-week period, once a day, 5 days a week , 2 Gy per fraction. Radioactive elements used: 192Ir, 137Cs ,125I , and 198Au . Drugs Used in Chemotherapy: Bleomycin Cisplatin Methotrexate 5-flourouracil

34. Verrucous Carcinoms A warty, high grade variant of SCC. It is a predominantly exophytic overgrowth of well differentiated keratinizing epithelium having minimal atypia , locally destructive margins. Usually in elderly, on an average between 60-70 years . Most commonly on buccal mucosa and gingiva .

35. Clinical features: Appears papillary, with a pebbly surface, which is sometimes covered by a white leukoplakic film . Lesions on the gingiva may grow into the soft tissue and invade and destroy the underlying bone. Regional lymph nodes are enlarged and tender, simulating metastatic tumor. Pain and difficulty in mastication are the common complaints . Growth is usually slow and metastasis occurs late, if at all . It may become more aggressive if irradiated . Treatment and Prognosis: Conservative excision • Risk of anaplastic transformation if irradiated.

36. Malignant Melanoma A neoplasm of epidermal melanocytes. One of the most biologically unpredictable and deadly of all human neoplasias . The third most common cancer of skin (after BCC and SCC). Previously believed to be developed from junctional nevus, which is premalignant melanocytic dysplasia of some kind. It can arise de novo or from premalignant melanocytic dysplasia.

37. Etiological factors : A. Environmental factors : Sun exposure Artificial UV sources Socioeconomic status Fair skin, red hair No . of melanocytic nevi B. Genetic factors : Familial melanoma Xeroderma pigmentosum Risk factors for oral melanomas are unknown. Most of these are thought to arise de novo . Two growth phases: Radial Growth phase Vertical Growth phase

38. Cutaneous melanomas have been classified into : Superficial spreading melanoma Nodular melanoma Lentigo malignant melanoma Acral lentiginous melanoma Oral manifestations : Twice as common in men than in women. Most cases occur between 40 and 70 years. Predilection for the palate and maxillary gingiva. Usually appears as a deeply pigmented area, at times ulcerated and hemorrhagic, which tends to increase progressively in size. Oral melanomas exist in superficial spreading, acral lentiginous and nodular types.

39. ABCDE Rule in clinical diagnosis of Malignant Melanoma ASYMMETRY BORDER IRREGULARITY – with blurred, notched or ragged edges. COLOR IRREGULARITY – pigmentation is not uniform black, brown, red, tan, white and blue can all appear together. DIAMETER – greater than 6 mm growth in itself is a sign . ELEVATION

40. Treatment and Prognosis Surgical excision for oral melanomas, jaw resection and lymph node dissection. Women have a much better survival rates upto 50 years and then the rate declines. Nodular and superficial spreading melanomas have a much poorer prognosis than the LMM . Oral melanomas have a much poorer prognosis than the cutaneous ones.

41. Benign Tumors of Connective Tissue Origin

42. Most common benign soft tissue neoplasm of the oral cavity. Females: Males = 2:1 M ost commonly on the buccal mucosa along the plane of occlusion. A well defined, slow growing lesion, most common in the third, fourth, and fifth decades Appears as an elevated nodule of normal color with a smooth surface , and a sessile or pedunculated base. Fibroma ( Irritational fibroma, focal fibrous hyperplasia)

43. Treatment: Surgical Excision

44. Giant Cell Fibroma Clinical Features The giant cell fibroma is typically an asymptomatic sessile or pedunculated nodule, usually less than 1 cm in size with papillary surface . M andibular gingiva is affected twice as often as the maxillary gingiva. The tongue and palate also are common sites . Treatment and prognosis: Surgical Excision Fair prognosis, recurrence is rare.

45. Peripheral Ossifying Fibroma Reactive rather than neoplastic in nature . S ome peripheral ossifying fibromas are thought to develop initially as pyogenic granulomas that undergo fibrous maturation and subsequent calcification . O ccurs exclusively on the gingiva in maxillary arch incisor- cuspid region A ppears as a nodular mass, either pedunculated or sessile , usually arises from the interdental papilla, red to pink , and frequently ulcerated surface. Peripheral clacifying fibroblastic granuloma, ossifying fibroid epulis

46. Treatment and Prognosis: Elimination of possible irritants Local surgical excision The mass should be excised down to periosteum because recurrence is more likely if the base of the lesion is allowed to remain.

47. N eoplasm of bone with remarkable similarities with central cementifying fibroma 3 rd -5 th decades of life, female predilection. Typically asymptomatic with displacement of teeth Radiographic Features: well defined and unilocular with a sclerotic border. depending upon calcification, completely radiolucent to radio-opaque. Central Ossifying Fibroma

48. Treatment: Conservative surgical excision

49. Differences between POF and COF

50. Pyogenic Granuloma Misnomer Non-neoplastic , painless, nodular growth arising from the interdental papilla specially in anterior region of maxilla. Most commonly occurs in females, found to associated with female sex hormones. Aggravates in pregnancy thus called, pregnancy tumor. Causes: Gingival hyper-responsiveness to local traumas or irritations.

51. Clinical Features: Buccal interdental papilla > lingual IP Maxilla > Mandible Anterior region > posterior region Red-to-purple, Smooth or lobulated, Pedunculated or sessile, nodular lesion with increased vascularity & usually ulcerated surface, ranging from few mm to centimeters. Soft to palpation, mature lesions are firm to touch and reduced bleeding tendency.

52. Treament : Regress on its own after removal of local irritating factors Long standing fibrotic cases can be treated with conservative surgical excision

53. R elatively common tumor like growth of the oral cavity, reactive lesion caused by local irritation or trauma eg : tooth extraction, denture irritation or chronic infection Clinical Features: 5 th and 6 th decades of life, mostly females, mandible is affected more than maxilla, anterior and posterior region. Occurs exclusively on gingiva or edentulous alveolar ridge, presenting as red or reddish blue nodular mass, pedunculated or sessile, with or without surface ulceration, mostly less than 2 cm in size. Peripheral Giant Cell Granuloma

54. TREATMENT: local surgical excision down to the underlying bone with removal of source of irritation .

55. Aka Giant Cell Tumor, Giant cell lesion, non-neoplastic but aggressive lesion mimics neoplasm. Mostly females , mandible more than maxilla, majority in anterior region which frequently crosses midline. Asymptomati c, however, may be associated with pain, paresthesia , or perforation of the cortical bone plate Radiographically , unilocular or multilocular radiolucent lesion, well delinated but non-corticated borders. Central Giant Cell Granuloma

56. Treatment: Surgical Excision

57. Differences between CGCG & PGCG

58. Hemangioma Benign neoplasm of vascular tissue origin, with distinctive phases of proliferation and involution, which is present at birth and regresses later. Hemangioma of oral cavity isn’t that common, but head & neck is most common site.

59. According to Watson and McCarthy, Capillary hemangioma . Cavernous hemangioma . Angioblastic or hypertrophic hemangioma . Racemose hemangioma . Diffuse systemic hemangioma . Metastasizing hemangioma . Nevus vinous , or port- wine stain Hereditary hemorrhagic telangiectasis

60. Clinical Features: Occur in infants or children . Usually affects whites but rarely occurs in blacks. Female : male = 3:1 . Most common site of occurrence is lip, tongue, buccal mucosa, and palate . Most commonly affected facial bones are mandible , maxilla , and nasal bones . Intramuscular hemangiomas in the oral region are most commonly seen in the masseter . Oral lesions appears as a flat or raised , deep red or bluish red lesion which is seldom well circumscribed. They are readily compressible and fill slowly when relieved Two third of the central hemangiomas were located in the mandible . They are bone destructive lesions, often resembling cyst and causing root resorption , but vitality of teeth is not affected .

61. Treatment and Prognosis: Many congenital hemangiomas have been found to undergo spontaneous regression at a relatively early age. Cases which do not show such remission have been treated by : Surgery Radiation therapy Sclerosing agents, such as sodium morrhuate or psylliate , injected into the lesion Cryotherapy Prognosis is excellent since it does not become malignant or recur .

62. A benign hamartomatous hyperplasia of lymphatic vessels, with three-fourths of all cases occurring in the head and neck region. Classification suggested by Watson and McCarthy ; simple lymphangioma cavernous lymphangioma cellular or hypertrophic lymphangioma diffuse systemic lymphangioma cystic lymphangioma or hygroma Lymphangioma

63. Clinical Features: The intraoral form most commonly occurs on the tongue . Superficial lesions are manifested as papillary lesions which may be of the same color or of a slightly redder hue . Deeper lesions appear as diffuse nodules or masses without any significant change in surface texture or color. “The irregular nodularity of the surface of the tongue with gray and pink projections, and when associated with macroglossia , is pathognomonic of lymphangioma .” Lip involvement referred to as macrocheilia . An unusual form of lymphangioma occurs in the alveolar ridge in neonates which exhibits small blue-domed fluid-filled lesions on the alveolar ridges of black newborns.

64. Treatment and Prognosis : Surgical excision is the treatment of choice, since the lymphangioma is more radioresistant and insensitive to sclerosing agents. Spontaneous regression is rare. Because of the nonencapsulated and ‘infiltrating’ nature of the lymphangioma , complete removal is often impossible without excessive removal of surrounding normal structures.

65. Odontogenic Tumors

66. Classification of Odontogenic Tumors

67. Ameloblastoma ( Adamantinoma , adamantoblastoma , multilocular cyst) Coined by Churchill in 1934 to replace ‘ adamantinoma ’ given by Malassez in 1884. “The ameloblastoma is a true neoplasm of enamel organ type tissue which does not undergo differentiation to the point of enamel formation.” - WHO Definition “A tumor that is ‘usually unicentric , nonfunctional, intermittent in growth, anatomically benign and clinically persistent’.” - Robinson Second most common odontogenic neoplasm

68. Origin of Ameloblastoma : Cell rests of the enamel organ, either remnants of the dental lamina or remnants of Hertwig’s sheath, the epithelial rests of Malassez . Epithelium of odontogenic cysts, particularly the dentigerous cyst , and odontomas . Disturbances of the developing enamel organ. Basal cells of the surface epithelium of the jaws. Heterotopic epithelium in other parts of the body, especially the pituitary gland . Presently, it is thought that it is likely the result of alterations or mutations in the genetic material of cells that embryologically preprogrammed for tooth development. Genetics: Overexpression of TNF-α, antiapoptotic proteins (Bcl-2, BclxL ), and interface proteins (fibroblast growth factor [FGF ], matrix metalloproteinases [MMPs]

69. Variants of Ameloblastoma Central ( intraosseous ) ameloblastoma – most common , 2nd common odontogenic tumor Peripheral ( extraosseous ) ameloblastoma – soft tissue Pituitary ameloblastoma ( cranio pharyngioma , Rathke’s pouch tumor ) WHO types of Ameloblastoma Solid / multicystic Extraosseous or peripheral Desmoplastic Unicystic

70. Clinical Features: Central Type 10 years through 90 years with peak at 33-39 years. Only 10% in below 10 years. No significant sex predilection Occurs in all areas of the jaws - mandible is the most commonly affected area (more than 80%) Molar angle ramus area > 3 times more commonly than the premolar and anterior regions combined. It may be either solid or unicystic type Usually asymptomatic and are discovered either during routine radiographic examination or because of asymptomatic jaw expansion

71. Peripheral ( extraosseous ) Ameloblastoma O ccurs in the soft tissue outside and overlying the alveolar bone . Originate from either surface epithelium or remnants of dental lamina Slight predilection for males, 2 : 1 ratio of mandible over the maxilla Found as nodules on the gingiva, varied in size from 3 mm- 2 cm in diameter, resembles basal cell carcinoma of gingiva. Relatively innocuous, lacks the persistent invasiveness of the intraosseous lesion Very limited tendency for recurrence

72. Pitutary Ameloblastoma Usually found in suprasellar area, grows as a pseudoencapsulated mass Patient may have endocrine disturbance, drowsiness or even toxic symptoms. Adamantinoma of long bones True nature of the lesion is still unknown. Occurred in the tibia in approximately 90 %, sometimes in ulna, femur and fibula

73. Radiographic Features: Unilocular or multilocular radiolucency, with usually smooth but in advanced lesions scalloped, sclerotic margins. tumor exhibits a compartmented appearance w ith septa of bone extending into the radiolucent tumor mass which gives it a Honey Comb or soap bubble.

74. J aw expansion or thinning of the cortical plate

75. Histological Features: Six histopathologic subtypes Follicular Acanthomatous Plexiform Granular cell Basal cell Desmoplastic Disconnected islands, strands, and cords within the collagenized fibrous CT stroma Consist of tall columnar cells with hyperchromatic nuclei, reverse polarity of the nuclei, and subnuclear vacuole - characteristic palisading pattern

76. Treatment and Prognosis: Include both radical and conservative surgical excision, curettage , chemical and electrocautery , radiation. Or a combination of surgery and radiation . Curettage is least desirable - highest incidence of recurrence Radiation - highly radioresistant , so not preferred now Surgical excision with 1mm of safety margins with chemical cauterization with carnoy’s solution is treatment of choice. carnoy’s solution: 60% ethanol, 30% chloroform and 10% glacial acetic acid,1gm of ferric chloride

77. Aka Pindborg tumor Uncommon benign odontogenic tumor which is exclusively epithelial in origin Locally aggressive tumor, comprises 1% of all odontogenic tumor. Histogenesis : Stratum intermedium and Strands of remnants of dental lamina, as suggested by Pindborg Amyloid depositions are believed to be immunological response to the startum intermedium cells Calcifying Epithelial Odontogenic Tumor

78. Clinical Features: Affects populations over wide range of age group of 8-92 years with predilection for 4 th to 6 th decades. No specific gender predilection Mandible is affected twice more than maxilla Molar-ramus-angle region is most common sites, thrice common than in premolars region. Asymptomatic, expansile , hard bony swellings, may be associated with unerupted or impacted tooth. Tumor shows bucco -lingual extension with thining of cortical plate, and egg-shell cracking Tipping of tooth, rotations, root resorption , mobility of tooth in affected area is a common finding.

79. Radiographic features: Mixed radiolucent lesion Unilocular or multilocular radiolucency, with ill-defined margins and flecks of calcifications giving wind-driven snow appearance , Sometimes unerupted teeth is present inside lesion mimicking dentigerous cyst.

80. Histology: Proliferation of polyhedral epithelial cells in islands, strands, cords or sheets which sometimes show cribiform appearance . Homogenous, amyloid depositions among the cells, and calcifications in forms of “ liesegang ring pattern”. Apple green birefringence in polarized light Treatment and prognosis: Small lesions: excision or curettage Larger, recurrent lesions: segmental resection Atypical CEOT or Malignant ex CEOT  radial resection+ radiotherapy+ chemotherapy Recurrance rate: 10-20%

81. Adenomatoid Odontogenic Tumors Uncommon tumor, mostly associated with unerupted maxillary canine Histogenesis Unknown Odontogenic ; because arises in tooth areas, and histologically resembles cells of dental lamina

82. Clinical Features: Younger patients with 69% occurring in second decade of life. Female : Male = 2: 1 (over 30 years, F:M = 1:2) (Gingival lesions F:M= 14:1) Maxilla > mandible, anterior to canine 2/3 rd tumor: 2/3 rd occurs in maxilla 2/3 rd in young patients 2/3 rd in association with unerupted teeth 2/3 rd of affected teeth are canines Asymptomatic, bony swelling, in maxillary anterior regions mostly resulting into facial asymmetry and most commonly missing canines or delayed eruption. When occurs in mandible, bucco -lingual extension can lead to fractures of mandible.

83. Radiographic Features: Unilocular to multilocular radiolucency with some foci of calcification, smooth sclerotic or corticated borders. Erosions of cortical plates and displacement of tooth more than resorption .

84. Treatment and Prognosis: Conservative Surgical excision Recurrence is rare.

85. Odontomas are hamartomas or malformations of dental tissues and not neoplasms Similar to teeth: do not develop further once calcified may erupt into the mouth form during the period of odontogenesis can become carious (if exposed to saliva ) Both epithelium and mesenchymal cells exibit complete differentiation resulting in functional ameloblast and odontoblast Organisation of odontogenic apparatus fails to reach normal state of morphodifferentiation Odontomas

86. Two types: Compound O dontoma : Moderately developed and well arranged all tooth structures Complex Odontomas : tooth like materials (enamel, dentin) haphazardly arranged which don’t show any resemblance to tooth.

87. Clinical Features: Age: 10 and 19 years Sex: No predilection Site: Maxilla > Mandible Anterior region ( maxilla)- Compound Posterior Jaw- Complex Hard painless masses, usually accidently recorded on routine radiographic examination. Associated problems: Caries Abscess formation Prevent eruption Displace teeth Cyst formation

88. A. Compound Odontoma Radiographic Features: Many separate, small denticles Structure of normal teeth; small and simpler gross morphology

89. Dense opacity Radiolucent rimming ( develop within a dental follicle) If infected, the calcified tissues may be mistaken for a sequestrum Radiographic Features: B . Complex odontoma

90. Treatment: A. Compound Odontoma Enucleated surgically Complications: Dentigerous cyst Gardner's syndrome of intestinal polyposis: multiple odontomas Odontoameloblastoma B. Complex Odontoma Enucleated surgically Complications: potential obstructions to the eruption focus of infection cosmetic lesions

91. References: Robbin’s Basic Pathology, 10 th etd . Shafer’s Textbook of Oral Pathology, 5 th etd . Oral and Maxillofacial Pathology, Neville, 4 th etd . Burket’s Oral Medicine, 12 th etd .