Odontogenic Tumors PDF

Oral pathology 1 Odontogenic tumors 2  Odontogenic tumors Definition Odontogenic tumors are tumors arising from Tooth forming tissues and their remnants (odontogenic tissues). Therefore, they are found exclusively in the mandible and ma...

Oral pathology 1 Odontogenic tumors 2  Odontogenic tumors Definition Odontogenic tumors are tumors arising from Tooth forming tissues and their remnants (odontogenic tissues). Therefore, they are found exclusively in the mandible and maxilla (and occasionally gingiva) Some of these lesions are true neoplasms. Others may represent tumor-like malformations (hamartomas). The etiology and pathogenesis of this group of lesions are unknown. 3 Dr.Naglaa Kamal  The origin of odontogenic tumors (Tooth forming tissues) Ectodermal Mesenchymal (epithelial) (connective tissue) Dental lamina Dental Papilla (Epithelial Rests of Serres) Enamel Organ Dental Sac (follicle) (ReducedEnamelEpithelium) Epithelial Root Sheath of Hertwig’s (Epithelial Rests of Malassez) 4 Dr.Naglaa Kamal  Odontogenic tissue 5 Dr.Naglaa Kamal  Classification of Odontogenic tumors Benign Epithelial Odontogenic Tumors Ameloblastoma Adenoid ameloblastoma Adenomatoid Metastasizing odontogenic ameloblastoma tumor Squamous Calcifying Epithelial odontogenic tumor Odontogenic Tumor 6 Dr.Naglaa Kamal  Classification of Odontogenic tumors Benign Mesenchymal Odontogenic Tumors Odontogenic Myxoma Cemento- Odontogenic ossifying Fibroma Fibroma Cementoblastoma 7 Dr.Naglaa Kamal  Classification of Odontogenic tumors Benign Mixed Odontogenic Tumors Odontoma Primordial Ameloblastic odontogenic tumor Fibroma Dentinogenic ghost cell tumour 8  Classification of Odontogenic tumors Malignant Odontogenic Tumors Ameloblastic Primary intraosseous Odontogenic carcinoma carcinoma, NOS sarcomas Sclerosing Clear cell odontogenic odontogenic carcinoma carcinoma Odontogenic Ghost cell odontogenic carcinosarcoma carcinoma 9  Odontogenic General Features tumors Clinically, odontogenic tumors are asymptomatic, although they may cause jaw expansion, movement of teeth, root resorption, and bone loss. Histologically, odontogenic tumors tend to mimic the cell or tissue of origin. So,they may resemble soft tissues of the enamel organ or dental pulp, or they may contain hard tissue elements of enamel, dentin, and/or cementum. 1 Dr.Naglaa Kamal 0  Epithelial Odontogenic Tumors 1 Dr.Naglaa Kamal 1  Epithelial Odontogenic Tumors 1.Ameloblastoma Definition ✓ It is a benign locally aggressive epithelial odontogenic neoplasm. ✓ It is slowly growing. ✓ It is the most common odontogenic neoplasm. 9 Dr.Naglaa Kamal  Epithelial 1.Ameloblastoma Odontogenic Tumors It occurs in 3 different types with different clinical, radiographic and histological features: A. Conventional solid or multicystic (intraosseous), (about 86% of Cases) with its histological variants: -Follicular. -Plexiform. B. Unicystic (intraosseous) (about 13% of cases) with its histological variants: -Luminal. -Intraluminal. -Mural. C. Peripheral (extraosseous) (about I % of all cases). Dr.Naglaa Kamal 10  Epithelial Odontogenic Tumors 1.Ameloblastoma Origin (histogenesis) They may arise from: Dental lamina or its remnants. Enamel organ or its remnants. Epithelial lining of an odontogenic cyst. Basal cells of the oral mucosa. 14 Dr.Naglaa Kamal 1.Ameloblastoma A. Conventional Ameloblastoma Clinical Features Age: It occurs mostly in the fourth and fifth decades of life. Site: About 85% occur in the mandible. most often in the molar-ascending ramus area. About I5% occur in the maxilla, usually in the posterior region. If untreated, the lesion may grow slowly to a massive size. 15 Dr.Naglaa Kamal 1.Ameloblastoma A. Conventional Ameloblastoma Radiographic Features ✓ It mostly appear as multilocular radiolucent lesion. “Soap bubble" appearance occurs when the radiolucent loculations are large. “Honeycomb" appearance occurs when the loculations are small. ✓ It may appear as unilocular radiolucent defects. ✓ In many cases, an unerupted tooth, most often a mandibular third molar, is associated with the radiolucent defect. Dr.Naglaa Kamal 13 1.Ameloblastoma A. Conventional Ameloblastoma 14 Dr.Naglaa Kamal  Histopathologic Variants of Conventional Ameloblastoma 1. Follicular 2. Plexiform a. Cystic (multicystic) b. Acanthomatous Variants of follicular ameloblastoma c. Granular d. Basaloid e. Desmoplastic N.B. The difference in histopathologic features Dr.Naglaa Kamal has no clinical significance. 15  Epithelium: Form descrete Islands or nests (resemble enamel organ epithelium) surrounded by connective tissue stroma. Epithelial nests Central cells consist of loosely arranged angular cells resembling the stellate reticulum of an enamel organ. Surrounding layer consists a single layer of tall columnar ameloblast –like cells. The nuclei of these cells are located at opposite pole to the basement membrane (reversed polarity). Dr.Naglaa Kamal 16  a. Cystic follicular: Results from cystic degeneration of the stellate reticulum like cells which will produce microcyst. The microcyst unite to form larger macrocystic spaces surrounded by flat cells. 20 Dr.Naglaa Kamal  b. Acanthomatous ameloblastoma: Occurs due to squamous metaplasia of the stellate reticulum like cells of follicular ameloblastoma. Often associated with keratin formation. 21 Dr.Naglaa Kamal c. Granular cell ameloblastoma: Occurs when groups of stellate reticulum like cells show transformation to granular cells. -The granular cells are: -Cuboidal or rounded in shape. - Cytoplasma contains eosenophilic granules. -Nucleus is pushed against the cell membrane. 22 Dr.Naglaa Kamal d. Basaloid ameloblastoma: Composed of nests of uniform basaloid cells. No stellate reticulum is present in the central portions of the nests. The peripheral cells about the nests tend to be cuboidal rather than columnar. 23 Dr.Naglaa Kamal  e. Desmoplastic ameloblastoma: contains small islands and cords of odontogenic epithelium in a densely collagenized stroma. 24 Dr.Naglaa Kamal  Consists of a network of long, anastomosing cords of odontogenic epithelium lined by columnar or cuboidal ameloblast-like cells and in the center of the cords stellate reticulum like cells are present. The cords are surrounded by connective tissue stroma. Cystic formation occurs by stromal breakdown (not epithelial). In stromal degeneration, stromal blood vessels appear dilated and known as haemangio-ameloblastoma. Dr.Naglaa Kamal 22  Epithelial 1.Ameloblastoma Odontogenic Tumors It occurs in 3 different types with different clinical, radiographic and histological features: A. Conventional solid or multicystic (intraosseous), (about 86% of Cases) with its histological variants: -Follicular. -Plexiform. B. Unicystic (intraosseous) (about 13% of cases) with its histological variants: -Luminal. -Intraluminal. -Mural. C. Peripheral (extraosseous) (about I % of all cases). Dr.Naglaa Kamal 23 1. Ameloblastoma B. Unicystic Ameloblastoma Unicystic ameloblastoma is a type of ameloblastoma that may originates: De novo as a neoplasm or, May arise as a result of neoplastic transformation of epithelial lining of dentigerous. Clinically: Most cases are found in the mandible, usually in the posterior regions. Radiographically: Appears as unilocular radiolucency that may contain crown of an unerupted Dr.Naglaa Kamal mandibular third molar. 24  Histopathologic variants of unicystic ameloblastoma Luminal unicystic Intraluminal unicystic Mural unicystic ameloblastoma ameloblastoma ameloblastoma The changes occur in the lining of the cyst that One or more nodules consists totally or partially The fibrous wall of of ameloblastoma of ameloblastic epithelium. the cyst is infiltrated project from This demonstrates a basal by the cystic lining into the layer of columnar or follicular or plexiform lumen of the cyst similar cuboidal cells with ameloblastoma. to plexiform pattern. hyperchromatic nuclei with reverse polarity The overlying epithelial cells consist of stellate reticulum lDikr.eNace gllalsa. Kamal 25  Histopathologic variants of unicystic ameloblastoma Luminal unicystic Intraluminal unicystic Mural unicystic ameloblastoma ameloblastoma ameloblastoma 26 Dr.Naglaa Kamal 1. Ameloblastoma C. Peripheral Origin Ameloblastoma It may arises from rests of dental lamina beneath the oral mucosa or from the basal epithelial cells of the surface epithelium. Histopathologically, these lesions have the same features as the intraosseous form. Connection of the tumor with the basal layer of the surface epithelium is seen in about 50% of cases. Clinically It is usually a painless, nonulcerated gingival or alveolar mucosal swelling. most commonly found on the posterior gingival and alveolar mucosa. more common in mandible than maxilla Radiographically: Dr.Naglaa Kamal Negative in x-ray. 27  Epithelial 2. Adenomatoid Odontogenic Tumors odontogenic tumor Definition It is a benign epithelial odontogenic tumor that contains ductlike structures. Origin It is derived from enamel organ , or from remnants of dental lamina. Clinical Features Age: most cases appearing in the second decade. Site: Most lesions appear in the anterior portion of the maxilla. Size: Most adenomatoid odontogenic tumors are Dr.Naglaa Kamal relatively small. 29  Epithelial 2. Adenomatoid Odontogenic Tumors odontogenic tumor Radiographic Features: ✓ the tumor appears as a will circumscribed unilocular radiolucency. ✓ It may involves the crown of an unerupted tooth, most often a canine. ✓ The lesion may contains fine radiopaque calcifications. 32 Dr.Naglaa Kamal  Epithelial 2. Adenomatoid Odontogenic Tumors odontogenic tumor Histopathologic Features 1. The tumor is usually surrounded by a thick , fibrous capsule. 2. the tumor is composed of spindle shaped epithelial cells that form sheets or strands in a scanty fibrous stroma. 3. The epithelial cells may form rosette like structures with a central space, which contain small amounts of eosinophilic material. 33 Dr.Naglaa Kamal  Epithelial 2. Adenomatoid Odontogenic Tumors odontogenic tumor Histopathologic Features 4. The tubular or duct like structures are the characteristic feature of this tumor. These consist of a central space surrounded by a layer of columnar or cuboidal epithelial cells. The nuclei of these cells tend to be polarized away from the central space. 5. Small foci of calcification may also be scattered throughout the tumor. 34 Dr.Naglaa Kamal  Epithelial 2. Adenomatoid Odontogenic Tumors odontogenic tumor 35 Dr.Naglaa Kamal  Epithelial 3.Calcifying epithelial Odontogenic Tumors odontogenic tumor (Pindborg tumor) Definition It is a benign epithelial odontogenic tumor. It is a slowly growing tumor. Origin It is derived from enamel organ , or from remnants of dental lamina. Clinical Features Age: most cases appearing in the fourth decade. Site: Most lesions appear in the posterior area of the mandible. 36  Epithelial 3.Calcifying epithelial Odontogenic Tumors odontogenic tumor (Pindborg tumor) Radiographic Features ✓ the tumor appears as a will circumscribed unilocular or multilocular radiolucent radiolucency. ✓ It may be associated with an impacted tooth, most often a mandibular third molar. ✓ The lesion may be entirely Radiolucent or it may contains radiopaque calcifications. 37 Dr.Naglaa Kamal  Epithelial 3.Calcifying epithelial Odontogenic Tumors odontogenic tumor (Pindborg tumor) Histopathologic Features 1. tumor has discrete islands, strands, or sheets of polyhedral epithelial cells in a fibrous stoma. 2. Nuclei of the epithelial cells show variation in size and shape. 38 Dr.Naglaa Kamal  Epithelial 3.Calcifying epithelial Odontogenic Tumors odontogenic tumor (Pindborg tumor) Histopathologic Features 3. Large areas of amorphous, eosinophilic, hyalinized extracellular material are also present. 4. Calcifications, which are a distinctive feature of the tumor, develop within the eosinophilic material and form concentric rings known as Liesegang ring calcifications. 39 Dr.Naglaa Kamal  Epithelial 4.Adenoid Odontogenic Tumors Ameloblastoma Definition Is the new entity added in the odontogenic lesions. It is a hybrid benign odontogenic tumor which shows combined histopathological features of both ameloblastoma and adenomatoid odontogenic tumor. 40 Dr.Naglaa Kamal  Epithelial 4.Adenoid Odontogenic Tumors Ameloblastoma Clinical Features Age: 2nd–5th decade of life Site: More than two-third cases reported in mandible. 41 Dr.Naglaa Kamal  Epithelial 4.Adenoid Odontogenic Tumors Ameloblastoma Radiographic Features ✓ May be unilocular or multilocular radiolucency ✓ May also appear as mixed density due to the presence of dentinoid. 42 Dr.Naglaa Kamal  Epithelial 4. Adenoid Odontogenic Tumors Ameloblastoma Histopathologic Features 1. composed of cribriform architecture and ductlike structures, and frequently includes dentinoid. 2. epithelium resembling conventional ameloblastoma, duct-like spaces, focal whorled cellular condensations reminiscent of morules 3. clear cells, focal ghost-cell keratinization are reported. 43  Epithelial 4. Adenoid Odontogenic Tumors Ameloblastoma Histopathologic Features (E) cribriform arrangement of the AM-like epithelial component, duct-like spaces. (F) whirling or morules structures. (G) Clear-cell clusters and dentinoid matrix deposits. (H) occurrence of ghost cells. 44  May be unilocular or multilocular Epithelial 4. Adenoid Odontogenic Tumors Ameloblastoma Histopathologic Features 45 Dr.Naglaa Kamal  Epithelial 5. Metastasizing Odontogenic Tumors Ameloblastoma Definition An ameloblastoma that has metastasized despite its benign histopathological appearance. The lungs and Cervical lymph nodes have been regarded as common site for metastasis. Spread to vertebrae, other bones, and viscera has also occasionally been confirmed. 46 Dr.Naglaa Kamal  Epithelial 5. Metastasizing Odontogenic Tumors Ameloblastoma Radiographic Features ✓ The radiographic findings of malignant ameloblastoma may be essentially the same as those in typical non- metastasizing ameloblastoma. 47  Epithelial 6. Squamous Odontogenic Tumors Odontogenic Tumor Definition is a rare benign odontogenic neoplasm. Origin Dental lamina rests or the epithelial rests of Malassez. Clinically: Age: from 8 to 74 years (average age, 38). Site: no site of predilection. painless or mildly painful gingival swelling, often associated with mobility of the associated teeth. 48 Dr.Naglaa Kamal  Epithelial 6. Squamous Odontogenic Tumors Odontogenic Tumor Radiographically: ✓ may be a triangular radiolucent defect lateral to the root or roots of the teeth ✓The radiolucent area may be somewhat ill defined or may show a well defined, ✓corticated margin. ✓May displace or cause resorption of teeth in the area of the tumor. 40  Epithelial 6. Squamous Odontogenic Tumors Odontogenic Tumor Histopathologic Features varying-shaped islands of bland-appearing squamous epithelium in a mature fibrous connective tissue stroma. The peripheral cells of the epithelial islands do Not show the reverse of polarization seen in ameloblastoma. 50 Dr.Naglaa Kamal  Epithelial 6. Squamous Odontogenic Tumors Odontogenic Tumor Histopathologic Features Vacuolization and individual cell keratinization within the epithelial islands Laminated calcified bodies and globular eosinophilic structures probably represents dystrophic calcification. 51 Dr.Naglaa Kamal  Mesenchymal Odontogenic Tumors 38 Dr.Naglaa Kamal  Mesenchymal 1. Odontogenic Odontogenic Tumors Myxoma Definition: Odontogenic myxoma is a locally destructive benign mesenchymal odontogenic neoplasm that mimics microscopically the dental pulp or dental follicle. Origin Odontogenic mesenchyme. Clinically: Age: Young adults (25 to 30 years). Site: The mandible is involved more commonly than the maxilla. It is a rapidly growing lesion. Dr.Naglaa Kamal 39  Mesenchymal 1. Odontogenic Odontogenic Tumors Myxoma Radiographically: ✓ The myxoma appears as a multilocular radiolucency (honeycomb or soap bubble appearance) ✓ May displace or cause resorption of teeth in the area of the tumor. 40 Dr.Naglaa Kamal  Mesenchymal 1. Odontogenic Odontogenic Tumors Myxoma Histopathologic Features: ✓ The tumor is composed stellate or spindle-shaped cells with long anastomosing processes in faint basophilic myxoid (mucoid) stroma that contains few collagen fibrils. 41 Dr.Naglaa Kamal  Mesenchymal 2.Cementoblastoma Odontogenic Tumors (True cementoma) Definition It is a benign odontogenic neoplasm of cementoblasts. Origin Dental sac. Clinically Age: It occurs before 25 years of age. Site: Most cases arise in the mandibular premolar molar region. Almost 50% involve the first permanent molar. It is associated with the root of a vital tooth. Dr.Naglaa Kamal 42  Mesenchymal 2.Cementoblastoma Odontogenic Tumors (True cementoma) Radiographically ✓ The tumor appears as a radiopaque mass that is fused to one or more tooth roots and is surrounded by a thin radiolucent rim. ✓ There is root resorption and fusion of the tumor with the tooth. 57 Dr.Naglaa Kamal  Mesenchymal 2.Cementoblastoma Odontogenic Tumors (True cementoma) Histopathologic Features ✓ Tumor consists of dense mass of mineralized cementum with numerous basophilic reversal lines. The periphery of the lesion is composed of uncalcified matrix. 58 Dr.Naglaa Kamal  Mesenchymal 3.Cemento-ossifying Odontogenic Tumors Fibroma (COF) Definition is a fibro-osseous lesion characterized by varied patterns of bone formation in a fibroblastic stroma Cemento-ossifying fibroma can be classified according to site of origin as Central cemento-ossifying fibroma (CCOF) arises from cells of periodontal ligament in the apical area Soft tissue counterpart is referred to as peripheral cemento-ossifying fibroma (PCOF) 42 Dr.Naglaa Kamal  Mesenchymal 3.Cemento-ossifying Odontogenic Tumors Fibroma (COF) Hyperparathyroidism jaw tumor syndrome (HPT JT) predisposes to a triad occurrence: Multiple maxillary or mandibular cemento- ossifying fibroma Parathyroid adenoma or carcinoma Renal and uterine tumors  Mesenchymal 3.Cemento-ossifying Odontogenic Tumors Fibroma (COF) Origin odontogenic or from periodontal ligament progenitor cells Clinically Site: Most cases arise in the mandibular premolar molar region. Grows slowly but can reach a considerable size if left untreated Smaller lesions are asymptomatic Larger / solitary lesions present as painless swelling that causes jaw expansion, facial asymmetry, tooth divergence Extension to the nasal septum, orbital floor and infraorbital foramen Dr.Naglaa can be seen in larger lesions Kamal 42  Mesenchymal 3.Cemento-ossifying Odontogenic Tumors Fibroma (COF) Radiographically ✓ Radiological findings vary according to maturity of lesion; early lesions show well defined corticated radiolucency and over time, lesion becomes progressively more radiopaque 62 Dr.Naglaa Kamal  Mesenchymal 3.Cemento-ossifying Odontogenic Tumors Fibroma (COF) Radiographically ✓Well circumscribed, unilocular lesion with centrifugal pattern of growth ✓Larger lesions show expansion, thinning and perforation of buccal and lingual cortex and involvement of the lower border of mandible 63 Dr.Naglaa Kamal  Mesenchymal 3.Cemento-ossifying Odontogenic Tumors Fibroma (COF) Histopathologic Features ✓ Well defined lesion; may have thin fibrous capsule ✓Well demarcated margin from surrounding normal bone 64 Dr.Naglaa Kamal  Mesenchymal 3.Cemento-ossifying Odontogenic Tumors Fibroma (COF) Histopathologic Features ✓Lesion consists of variable proportion of fibrous and mineralized tissue, more heavily mineralized centrally; it shows variation in the amount and type of mineralization, even within a single lesion 65 Dr.Naglaa Kamal  Mesenchymal 3.Cemento-ossifying Odontogenic Tumors Fibroma (COF) Histopathologic Features ✓Woven to lamellar bone, osteoid and dense acellular or paucicellular basophilic rounded cementum-like calcifications may all be present ✓Osteoblastic rimming of bone trabeculae is frequent 66 Dr.Naglaa Kamal  Mesenchymal 3.Cemento-ossifying Odontogenic Tumors Fibroma (COF) Histopathologic Features ✓Stroma is fibroblastic with areas of hypercellularity and nuclear hyperchromasia ✓No significant atypia and mitoses are infrequent 67 Dr.Naglaa Kamal  Mixed Odontogenic Tumors 45 Dr.Naglaa Kamal  Mixed 1. Ameloblastic Odontogenic Tumors fibroma Definition It is a mixed benign odontogenic tumor in which the epithelial and mesenchymal tissues are both neoplastic. Clinically: Age: The first two decades of life. Site: The posterior mandible is the most common site. 46 Dr.Naglaa Kamal  Mixed 1. Ameloblastic Odontogenic Tumors fibroma Radiographically: ✓ A well defined unilocular or multilocular radiolucency. ✓ It may contain an un erupted tooth. 47 Dr.Naglaa Kamal  Mixed 1. Ameloblastic Odontogenic Tumors fibroma Histopathologic Features The epithelial portion of the tumor consists of long, narrow cords of odontogenic epithelium only two cells in thickness and are composed of cuboidal or columnar cells. In another pattern, the epithelia l cells form small discrete islands that resemble follicular ameloblastoma. These show peripheral columnar cells surround stellate reticulum like cells. 48 Dr.Naglaa Kamal  Mixed 1. Ameloblastic Odontogenic Tumors fibroma Histopathologic Features ✓ The mesenchymal portion of the tumor It is highly cellular and consists of stellate cells in a loose matrix resembling dental papilla. ✓ The tumor is usually surrounded with fibrous capsule. 72 Dr.Naglaa Kamal  Mixed 2. Odontoma Odontogenic Tumors Definition: Odontomas are mixed odontogenic tumors, since they are composed of both epithelial and mesenchymal dental hard tissues. Odontomas are considered to be developmental anomalies (hamartomas) rather than true neoplasms. 73 Dr.Naglaa Kamal  Mixed 2. Odontoma Odontogenic Tumors When fully developed, odontomas consist of enamel and dentin with variable amounts of pulp and cementum. Odontomas are further subdivided into compound and complex types. ✓ The compound is composed of multiple small tooth like structures. ✓ The complex odontoma consists of mass of enamel and dentin which bears no anatomic resemblance to a tooth. 74 Dr.Naglaa Kamal  Mixed 2. Odontoma Odontogenic Tumors Clinical Features Age: Most odontomas are detected during the first two decades of life. Site: The maxilla is affected slightly more often than the mandible. the compound type is more often seen in the anterior region, complex odontomas occur more often in the molar regions. 75 Dr.Naglaa Kamal  Mixed 2. Odontoma Odontogenic Tumors Radiographically the compound odontoma appears as a collection of tiny tooth like structures surrounded by a narrow radiolucent zone. The complex odontoma appears as a radiopaque mass with the radiodensity of tooth structure which is also surrounded by a narrow radiolucent rim. 76 Dr.Naglaa Kamal  Mixed 2. Odontoma Odontogenic Tumors Histopathologic Features ▪ The compound odontoma consists of multiple structures resembling small, single-rooted teeth with well organised dental tissue (enamel matrix, dentin, pulp) , contained in a loose fibrous matrix. 77 Dr.Naglaa Kamal  Mixed 2. Odontoma Odontogenic Tumors Histopathologic Features ▪ Complex odontomas consist of disordered mixture of dental tissues. The dentin encloses clefts or circular spaces which may contain small amounts of enamel matrix. 78 Dr.Naglaa Kamal  Mixed 3.Dentinogenic ghost cel Odontogenic Tumors tumor Definition: Benign, locally aggressive odontogenic neoplasm with a predominantly solid pattern of growth with high rates of recurrence. May be called Epithelial odontogenic ghost cell tumor OR Calcifying ghost cell odontogenic tumor 79  Mixed 3.Dentinogenic ghost Odontogenic Tumors cell tumor Clinical Features Age: Broad age range (11 - 79 years old); peak 40 - 60 years old. Site: posterior maxilla and mandible and rarely reported as gingiva or alveolar mucosal tumor Patients frequently present with asymptomatic swelling of the jaw 80 Dr.Naglaa Kamal  Mixed 3.Dentinogenic ghost cell Odontogenic Tumors tumor Radiographically Majority present as radiopaque lesions with well defined borders and a mixed radiodensity due to varying levels of calcification 81  Mixed 3.Dentinogenic ghost cell Odontogenic Tumors tumor Histopathologic Features ▪ Predominantly solid mass consisting of sheets of anastomosing cords and strands of odontogenic epithelium; microcystic development possible ▪Varying levels of dentinoid and cementum-like calcified collagenous matrix. 82  Mixed 3.Dentinogenic ghost cell Odontogenic Tumors tumor Histopathologic Features ▪Ameloblastic-like areas with palisading of basaloid cells ▪Odontogenic epithelial cells demonstrate round uniform basophilic nuclei and pale eosinophilic to clear cytoplasm ▪Background stellate reticulum-like proliferation. 83  Mixed 3.Dentinogenic ghost cell Odontogenic Tumors tumor Histopathologic Features ▪Admixed ghost cells: anucleate epithelial cells with pale cytoplasm containing cytoplasmic clearings representing the location of a previously resorbed nucleus or organelles. 84  Mixed 4. Primordial Odontogenic Odontogenic Tumors Tumor (POT) Definition: uncommon odontogenic tumor with biphasic morphology since its epithelial and mesenchymal components present an ameloblastomatous morphology and resemble the dental papilla differentiation, it is believed that POT development occurs during early odontogenesis since these microscopic features are found in the tooth germ normal tissues 85 Dr.Naglaa Kamal  Mixed 4.Primordial Odontogenic Odontogenic Tumors Tumor Clinical Features Age: first and second decades of life Site: mandible more than maxilla 86  Mixed 4.Primordial Odontogenic Odontogenic Tumors Tumor Radiographically unilocular radiolucent lesion associated with the crown of an unerupted tooth. 87  Mixed 4.Primordial Odontogenic Odontogenic Tumors Tumor Histopathologic Features ▪ 2 significant histopathological findings are essential to POT diagnosis ▪The first one is an abundant collagenous and/or fibromyxoid stroma exhibiting many spindle-to-ovoid cells resembling dental papilla. ▪ The second one is the presence of an odontogenic epithelium composed of cuboidal to columnar cells with clear cytoplasm and reverse nuclear polarity. This odontogenic epithelium resembles the inner enamel epithelium and is located in the periphery of the tumor 88  Mixed 4.Primordial Odontogenic Tumors Odontogenic Tumor Histopathologic Features 89  Mixed 4.Primordial Odontogenic Tumors Odontogenic Tumor Histopathologic Features 90  Malignant Odontogenic Tumors 9 1 Malignant Odontogenic Tumors 1. Ameloblastic Carcinoma NB Rarely, an ameloblastoma exhibits malignant behavior with rapid growth rate and development of metastases. Radiographic features denotes an aggressive lesion with ill-defined margin. Microscopically, the tumor shows The pattern of ameloblastoma in addition to cytologic features of malignancy. These include an increased nuclear- to-cytoplasmic ratio, nuclear hyperchromatism and the presence of mitoses. 28 Dr.Naglaa Kamal  Malignant 2. Sclerosing Odontogenic Odontogenic Tumors Carcinoma Clinical Features Age: the 5–7th decades most commonly, with a slight male predilection. Site: The mandibular premolar and molar region is more than the maxilla. locally aggressive accompanied by perineural and vascular invasion, as well as cortical bone loss. 93  Malignant 2. Sclerosing Odontogenic Odontogenic Tumors Carcinoma Histopathologic Features ▪This tumor is characterized by thin cords, strands, and small nests of epithelium in a densely sclerotic stroma. ▪ In some tumor foci, the density of the stroma may be sufficient to compress the epithelial component beyond detection in the absence of immunohistochemistry, thus rendering this entity a particularly challenging diagnosis in small sample sizes. ▪The epithelial cells demonstrate atypia, with nuclear pleomorphism. 94  Malignant 2. Sclerosing Odontogenic Odontogenic Tumors Carcinoma Histopathologic Features 95  Malignant 3. Clear cell odontogenic Odontogenic Tumors carcinoma (CCOC) Clinical Features Age: a wide age range (20–86 years), with a mean of 52.6 years and a female predilection. Site: mainly affects the mandible Clinically, it may present as a slow-growing painful swelling of the jaw, with an ill-defined radiographic appearance 96  Malignant 3. Clear cell odontogenic Odontogenic Tumors carcinoma (CCOC) Histopathologic Features ▪Predominant clear cell phenotype histologically. ▪CCOC can present three morphological patterns: (1) biphasic, consisting of nests of clear cells associated with cells presenting faint eosinophilic cytoplasm; (2) monophasic, composed only of clear cells; (3) ameloblastomatous, presenting ameloblast-like cells on the periphery of tumor cell islands 97  Malignant 3. Clear cell odontogenic Odontogenic Tumors carcinoma (CCOC) Histopathologic Features 98  Malignant 4. Ghost Cell Odontogenic Odontogenic Tumors Carcinoma (GCOC) Definition: GCOC is an extremely rare destructive and aggressive malignant odontogenic tumor GCOC are thought to originate from de novo, others arise from pre-existing calcifying odontogenic cyst (COC) or dentinogenic ghost cell tumor (DGCT) 99  Malignant 4. Ghost Cell Odontogenic Odontogenic Tumors Carcinoma (GCOG) Clinical Features Age: 4th and 5th decades, with a higher occurrence in males Site: common in maxilla 100  Mixed 4.Ghost Cell Odontogenic Odontogenic Tumors Carcinoma (GCOG) Histopathologic Features ▪Ghost cells are a prominent feature in the epithelial islands but is not a specific character of GCOC. ▪GCOGs are histologically characterized by ameloblastoma like epithelium with prominent ghost cells and cytological evidence of malignancy and dentinoid formation. 101  Mixed 4. Ghost Cell Odontogenic Odontogenic Tumors Carcinoma (GCOG) Histopathologic Features 102  Malignant 5. Primary intraosseous Odontogenic Tumors carcinoma-NOS (PIOC-NOS) Definition: is often difficult as the lesion must be differentiated from carcinomas that may invade the bone from the overlying soft tissues or from the tumors that have metastasized to the jaw from a distant site it may arise from reduced enamel epithelium or even odontogenic cysts 103  Malignant 5. Primary intraosseous Odontogenic Tumors carcinoma-NOS (PIOC-NOS) Clinical Features Age: between 55-60 years. Also, male predominant Site: common in mandible (the posterior body and ramus of the mandible) They appear as painless or painful jaw swelling with intact overlying mucosa 104  Malignant 5. Primary intraosseous carcinoma- Odontogenic Tumors NOS (PIOC-NOS) Radiographically appear as destructive jaw lesions 105  Malignant 5. Primary intraosseous Odontogenic Tumors carcinoma-NOS (PIOC-NOS) Histopathologic Features ▪Histologically are squamous carcinomas with well to moderate differentiation without prominent keratinization. The stroma may or may not exhibit an inflammatory infiltrate. ▪This is a diagnosis of exclusion and should be made after excluding all other mimickers like other subtypes of malignant odontogenic tumors and metastatic lesions. 106  Malignant 6. Odontogenic Odontogenic Tumors carcinosarcoma Definition: is associated with both mesenchymal and epithelial malignant cells in histology. EX: an ameloblastic carcinosarcoma (transformation of both the epithelial and mesenchymal elements of an ameloblastic fibroma). 107  Malignant 7. Odontogenic sarcoma Odontogenic Tumors Definition: Odontogenic sarcomas usually appear in the 3rd decade and are histologically associated with bland looking epithelial cells and malignant mesenchymal cells. EX: Ameloblastic Fibrosarcoma, ameloblastic dentinosarcomas or ameloblastic fibroodontosarcomas. 108