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Worksheetslecture 12
Total questions: 42
Worksheet time: 21mins
Which of the following represents a benign epithelial odontogenic tumour derived primarily from odontogenic epithelium?
Odontogenic fibroma
Ameloblastoma
Cemento-ossifying fibroma
Odontome
Odontogenic myxoma
Which tissue origin best explains the development of odontogenic myxoma?
A. Dental lamina
B. Dental follicle
C. Reduced enamel epithelium
D. Rests of Serres
E. Rests of Malassez
According to the WHO simplified classification, which of the following is categorised under benign mixed epithelial and mesenchymal odontogenic tumours?
Ameloblastoma
Odontogenic fibroma
Dentinogenic ghost cell tumour
Cementoblastoma
Clear cell odontogenic carcinoma
A 28-year-old woman presents with a painless swelling in the posterior mandible. Radiographs show a multilocular radiolucent lesion. Biopsy reveals epithelial islands resembling ameloblasts with stellate reticulum-like cells in a dense fibrous stroma. Which classification does this lesion belong to according to the WHO system?
Benign mesenchymal tumour
Benign mixed epithelial and mesenchymal tumour
Benign epithelial odontogenic tumour
Fibro-osseous lesion
Malignant odontogenic neoplasm
Which of the following best reflects the most common clinical site for a conventional ameloblastoma?
Anterior maxilla
Posterior mandible
Anterior mandible
Posterior maxilla
Midline of the palate
Why do ameloblastomas frequently appear multilocular on radiographs?
Presence of multiple cystic spaces within the tumor
Dense calcifications forming a honeycomb pattern
Infiltration into surrounding soft tissues
High vascularity causing radiographic anomalies
Associated with ghost cells
Which histopathological feature is characteristic of conventional ameloblastoma?
Odontogenic epithelium resembling a glandular pattern
Palisading columnar basal cells with reversed polarity
Dense fibrous stroma with absence of stellate reticulum like cells
Cellular atypia with hyperchromatic nuclei
Dentin-like material in the stroma
Which management approach is considered the standard of care for a conventional ameloblastoma involving the posterior mandible?
Marsupialisation and long-term observation
Incision and drainage followed by antibiotics
Simple enucleation without peripheral curettage
Wide surgical excision with 10 mm bone margins
Enucleation with decompression over several months
Which radiographic description most strongly suggests a conventional solid ameloblastoma?
Unilocular radiolucency with sclerotic margin around an impacted canine
Ill-defined radiolucency with sunburst periosteal reaction
Multilocular radiolucency with “soap-bubble” or “honeycomb” pattern
Ground-glass radiopacity with expansion
Cotton-wool opacity involving multiple quadrants
Which histological pattern of conventional ameloblastoma is characterised by epithelial islands with a peripheral layer of tall columnar cells showing reversed polarity?
Plexiform
Basal cell
Granular cell
Follicular
Acanthomatous
Which mutation has been identified in most ameloblastomas and activates the MAP kinase pathway?
KRAS mutation
PTCH gene mutation
TP53 mutation
BRAF V600E mutation
CDKN2A mutation
A 42-year-old patient presents with a painless swelling in the posterior mandible. Radiographs reveal a well-defined multilocular radiolucency causing buccal and lingual expansion. Biopsy shows epithelial islands with reversed polarity of basal cells and central stellate reticulum-like areas. Which diagnosis best fits these findings?
Odontogenic keratocyst
Giant-cell granuloma
Odontogenic myxoma
Conventional ameloblastoma
Central mucoepidermoid carcinoma
Which feature best distinguishes desmoplastic ameloblastoma from the conventional type?
Numerous large cystic spaces
Sparse epithelial islands within dense collagenous stroma
Abundant stellate reticulum-like cells
Pronounced ameloblast-like peripheral columnar cells
Frequent mitotic figures
A 40-year-old patient presents with a radiolucent lesion in the anterior maxilla showing a fine honeycomb pattern. Biopsy reveals sparse epithelial islands in a densely collagenous background with no obvious ameloblast-like cells. Which diagnosis best matches these findings?
Odontogenic myxoma
Desmoplastic ameloblastoma
Fibrous dysplasia
Calcifying epithelial odontogenic tumour
Squamous odontogenic tumour
Which feature best explains why metastasising ameloblastoma is not considered truly malignant?
It shows extensive nuclear atypia
It frequently transforms into carcinoma
Its metastases are histologically identical to benign ameloblastoma
The tumour arises only in the mandible
It rapidly causes neurological symptoms
A patient previously treated surgically for a mandibular ameloblastoma now presents with multiple pulmonary nodules. Biopsy of a lung lesion shows epithelial islands identical to those in the original tumour, without atypia or mitotic activity. Which explanation best fits this phenomenon?
True malignant transformation of the primary tumour
Development of primary lung carcinoma unrelated to the jaw lesion
Implantation metastasis resulting from previous surgery
Odontogenic cyst remnants in the lung
High-grade sarcomatous change in the tumour stroma
Which variant of unicystic ameloblastoma shows papillary projections into the cyst lumen without tumour islands infiltrating the wall?
Luminal
Mural
Intraluminal (plexiform unicystic)
Acanthomatous
Follicular
A 22-year-old male presents with a painless swelling near the angle of the mandible. Radiographs show a unilocular radiolucency associated with an unerupted molar. Biopsy reveals a cystic lesion lined by ameloblast-like cells. What is the most likely diagnosis?
Follicular keratocyst
Dentigerous cyst
Unicystic ameloblastoma
Ameloblastic fibroma
Eruption cyst
A 19-year-old presents with a unilocular radiolucency around an unerupted mandibular third molar. Biopsy shows a cyst lined by ameloblastomatous epithelium limited to a single layer with no wall infiltration. Ameloblast-like cells confined to the cyst lining. Which subtype best corresponds to this lesion?
Mural
Luminal
Solid
Intramural
Intraluminal
Why is the mural subtype of unicystic ameloblastoma more aggressive?
Ghost cells extend into surrounding bone.
Tumor islands infiltrate the fibrous cyst wall.
Calcifications form within the cyst wall.
Increased mitotic activity in epithelial cells.
Prominent vascularity enhances tumor growth.
What is a characteristic histological feature of calcifying epithelial odontogenic tumor?
Sheets of eosinophilic cells, pink-staining amyloid with Liesegang rings
Palisaded ameloblast-like cells with reversed polarity
Ghost cells in the stroma
Rounded islands of squamous epithelium
Fibrous stroma with myxoid ground substance
A 48-year-old patient is found to have a well-defined mixed radiolucent–radiopaque lesion in the posterior mandible. Histology shows eosinophilic epithelial cells with intercellular bridges, nuclear pleomorphism, and areas of amyloid exhibiting concentric calcifications. Which diagnosis best fits these findings?
Ameloblastoma
Calcifying epithelial odontogenic tumour
Odontogenic myxoma
Squamous odontogenic tumour
Cementoblastoma
Which microscopic feature of calcifying epithelial odontogenic tumour most often leads to confusion with carcinoma?
Dense collagenous stroma
Hyperkeratinised epithelium
Nuclear hyperchromatism and size variation
Abundant mitotic figures
Clear cell change
Which histological feature is characteristic of squamous odontogenic tumor?
A. Palisaded columnar cells
B. Rounded islands of squamous epithelium without peripheral palisading
C. Multinucleated giant cells
D. Dentin-like material in the stroma
E. Ghost cells
A 17-year-old female presents with a slow-growing, asymptomatic swelling in the anterior maxilla around an unerupted canine. Radiographs show a well-defined radiolucency resembling a dentigerous cyst with faint speckled calcifications. Which diagnosis best fits these features?
Odontogenic myxoma
Calcifying epithelial odontogenic tumour
Adenomatoid odontogenic tumour
Dentigerous cyst with dystrophic calcification
Ameloblastic fibroma
Which microscopic feature most strongly supports a diagnosis of adenomatoid odontogenic tumour?
Duct-like structures lined by columnar cells
Rounded squamous epithelial islands
Calcified ghost cells
Sheets of eosinophilic cells
Multinucleated giant cells
What is a common radiographic feature of adenomatoid odontogenic tumor?
Multilocular radiolucency
Unilocular radiolucency with fine speckled calcifications
Dense sclerotic lesion with a radiolucent border
Soap-bubble appearance
Target-like radiopacity
Which age group is most commonly affected by ameloblastic fibroma?
Infants under 2 years
Adults between 30–50 years
Patients aged 7–20 years
Elderly over 70 years
First decade only
Which microscopic feature most strongly supports the diagnosis of ameloblastic fibroma?
Sheets of squamous cells with keratin formation
Dense eosinophilic epithelial cells with amyloid
Cellular mesenchyme resembling dental papilla with epithelial strands
Duct-like structures lined by columnar cells
Large cementum masses fused to a root
Why is ameloblastic fibroma considered a mixed odontogenic tumor?
Both epithelial and mesenchymal components are neoplastic.
It contains mineralized dental tissues like enamel and dentin.
It shows transformation into ameloblastoma histologically.
Both epithelial and stromal components exhibit ghost cell formation.
It arises exclusively in association with unerupted teeth.
A 14-year-old presents with a slowly enlarging posterior mandibular swelling. Radiographs show a unilocular radiolucency displacing an unerupted second molar. Histology reveals epithelial islands with peripheral buds resembling cap-stage tooth germs within cellular mesenchyme. Which diagnosis best fits these findings?
Odontogenic myxoma
Adenomatoid odontogenic tumour
Ameloblastic fibroma
Dentigerous cyst
Ameloblastoma
Which statement best describes ameloblastic fibro-odontoma?
It forms enamel only and is a true neoplasm
It forms dentine only and behaves aggressively
It produces both enamel and dentine and represents a developing odontoma
It is a variant of ameloblastoma with calcifications
It is identical to ameloblastic fibroma histologically
Which radiographic appearance most commonly describes primordial odontogenic tumour?
Multiple radiopaque masses resembling osteoma
Large expanding radiolucency in the posterior mandible
Soap-bubble multilocularity extending to the ramus
Scalloped radiolucency between roots
Mixed radiolucent-radiopaque lesion with Liesegang rings
A 12-year-old presents with a large unilocular radiolucent lesion in the posterior mandible associated with an unerupted molar. Histology shows a solid mass of dental papilla-like tissue surrounded by a thin layer of ameloblast-like cells, but no dentine or enamel matrix. Which diagnosis best fits these findings?
Ameloblastic fibrodentinoma
Odontogenic myxoma
Primordial odontogenic tumour
Dentigerous cyst
Ameloblastoma
Which histological feature is seen in primordial odontogenic tumor?
Solid mass of dental papilla-like tissue with ameloblasts
Ghost cells with dystrophic calcification
Loose myxoid stroma with spindle-shaped fibroblasts
Sheets of eosinophilic cells with hyperchromatic nuclei
Woven bone trabeculae in fibrous stroma
Which feature most reliably distinguishes a compound odontome from a complex odontome?
Disorganized dental tissues without tooth-like structures
Well-formed tooth-like structures with enamel, dentin, and pulp
Presence of hyperplastic cementum
Prominent calcifications within ghost cells
Cellular mesenchymal stroma resembling dental papilla
Why is a compound odontome considered a developmental hamartoma rather than a true neoplasm?
It contains normal but disorganized dental tissues.
It arises from mesenchymal components exclusively.
It has no potential for malignant transformation.
It is associated with systemic syndromes like Gardner's syndrome.
It resolves spontaneously in most cases.
Which of the following is a characteristic histological feature of dentinogenic ghost cell tumor?
Ghost cells and dentinoid material in the stroma
Amyloid deposition with concentric calcifications
Palisaded columnar basal cells
Multinucleated giant cells with hemosiderin deposits
Loose, myxoid stroma with spindle-shaped fibroblasts
Which radiographic appearance is most characteristic of a mature complex odontome?
Ground-glass opacity
Multilocular radiolucency
Irregular, densely radiopaque mass
Radiolucency with curved septa
Cotton-wool sclerotic patches
A 9-year-old child presents with delayed eruption of an upper incisor. Radiographs show multiple small radiopaque structures within a single crypt in the anterior maxilla. Which diagnosis best fits these findings?
Complex odontoma
Compound odontoma
Hypercementosis
Dentigerous cyst
Odontogenic fibroma
What radiographic appearance is typically associated with CEOT?
Multilocular radiolucency with a soap-bubble appearance
Mixed radiolucent-radiopaque lesion with a well-defined border
Unilocular radiolucency without calcifications
Moth-eaten appearance with indistinct margins
Target-like radiopacity around tooth roots
A 45-year-old patient presents with a well-demarcated mixed radiolucent–radiopaque lesion in the mandibular body. Histology shows ameloblastoma-like epithelial islands, numerous ghost cells, and deposits of dentinoid. Which diagnosis best fits these findings?
Calcifying odontogenic cyst
Ameloblastoma
Dentinogenic ghost cell tumour
Odontogenic fibroma
Complex odontome
