Ameloblastoma Radiology and Ameloblastoma Treatment

Question 1. Classification of nonodontogenic tumors of the jaws.
(or)
Classification of soft tissue tumors of the jaw.
Answer:

1. Benign Tumors:

 

 

• Cartilage tumors:
  • Chondroma
  • Chondroblastoma
  • Chondromyxoid fibroma
• Muscles:
  • Leiomyoma
  • Rhabdomyoma
  • Granular cell myoblast oma
• Viral-induced tumors:
  • Squamous papilloma
  • Warts

Read And Learn More: Oral Medicine and Radiology Question And Answers

2. Malignant Tumors

• Malignant epithelial tumors:
  • Basal cell carcinoma
  • Squamous cell carcinoma
  • Verrucous carcinoma
  • Spindle cell carcinoma
  • Adenoid squamous cell carcinoma
  • Basaloid squamous cell carcinoma
  • Malignant melanoma
• Lymphoid tissue:
  • Hodgkin’s lymphoma
  • Non-Hodgkin’s lymphoma
  • Burkitt’s lymphoma
• Connective tissue:
  • Fibrosarcoma
  • Liposarcoma
• Muscles:
  • Leiomyosarcoma
  • Rhabdomyosarcoma
• Nerve tissue:
  • Neurosarcoma
  • Neurofibrosarcoma
• Vascular:
  • Angiosarcoma
  • Kaposi’s sarcoma
• Bone:
  • Osteosarcoma
  • Chondrosarcoma
  • Ewing’s sarcoma.

Question 2. Classify odontogenic tumors of the jaw and describe the clinicopathological and radiographic features of ameloblastoma.
Answer:

World Health Organization Classification (1992)

• Benign Odontogenic Tumors:
  • Odontogenic epithelium without odontogenic ectomesenchyme:
    • Ameloblastoma
    • Squamous odontogenic tumor
    • A calcifying epithelial odontogenic tumor (Pindborg tumor)
    • Clear cell odontogenic tumor
  • Odontogenic epithelium with odontogenic ectomesenchyme, with/without dental hard tissue formation:
    • Ameloblastic fibroma
    • Ameloblastic fibrodentinoma (dentinoma)
    • Ameloblastic fibro-odontoma
    • Odontoameloblastoma
    • Adenomatoid odontogenic tumor
    • Calcifying odontogenic cyst
    • Complex odontoma
    • Compound odontoma
  • Odontogenic ectomesenchyme with/without odontogenic epithelium:
    • Odontogenic fibroma
    • Myxoma (odontogenic myxoma, myxo-fibroma)
    • Cementoblastoma, and true cementoma.

Ameloblastoma Malignant:

• Odontogenic carcinomas:
  • Malignant ameloblastoma
  • Primary intraosseous carcinoma
  • Malignant variants of other odontogenic epithelial tumors
  • Malignant changes in odontogenic cysts
• Odontogenic sarcomas:
  • Ameloblastic fibrosarcoma (ameloblastic sarcoma)
  • Ameloblastic fibro-dentinosarcoma
  • Ameloblastic fibro-odontosarcoma

Ameloblastoma:

• Robinson defines ameloblastoma as a unicentric, nonfunctional, true neoplasm of enamel organ tissues with intermittent growth; behaves as a benign lesion but is locally aggressive.
• Ameloblastoma is the second most common type of tumor originating from odontogenic tissues.

Ameloblastoma Pathogenesis:

• It may be derived from:
  • Cell rests of the enamel organ.
  • Odontogenic cystic epithelium.
  • The basal cells of the surface epithelium.

Ameloblastoma Clinical Features:

• It affects individuals in the 4th and 5th decades of life.
• The mandible is frequently involved, molar ramus region being the common site (80%).

• In the early stage, it is slow-growing and asymptomatic.
  As a tumor enlarges, it causes expansion of jaw bone and facial deformity.
• The swelling will be hard, and non-tender or mildly tender.
  Eggshell crackling may be elicited due to thinning of the overlying bone.
• It is not capsulated. Though locally infil¬trate into the bone marrow, they do not metastasize. Occur both in the maxilla and mandible with a preference to the middle and posterior parts of the mandible.
• Peripheral ameloblastoma is a rare type and occurs on the gingiva. It is a noninvasive type, occurring in younger individuals.
• The mandibular premolar region is the reported site of preference. It grows up to 2-3 cm in size.

Ameloblastoma Radiographic Findings:

• A multilocular radiolucent lesion with a soap bubble or honeycomb pattern.
• The unilocular type is as a well-defined radiolucent lesion with a minimal sclerotic border and resembling a dentigerous cyst.
• Root resorption of adjacent teeth is common.

Ameloblastoma Treatment:

• For unilocular type—Curettage or enucleation.
• For multilocular type and solid pattern— tumor excision or partial resection of the jaw bone.

Question 3. Classify fibro-osseous lesions of the jaw. Describe the pathogenesis, clinical features, and radiographic appearance of fibrous dysplasia.
Answer: Fibro-osseous lesions of the jaw: In fibro-osseous lesions, the normal bone is replaced by fibroblasts and collagen fibers with varying amounts of a calcified substance.

World Health Organization Classification (1992)

• Osteogenic neoplasms:
  • Cemento-ossifying fibroma (cement- flying fibroma, ossifying fibroma).
• Non-neoplastic bone lesions:
  • Fibrous dysplasia of jaws
  • Cemento-osseous dysplasia:
    • Periapical cemental dysplasia (peri-apical fibrous dysplasia)
    • Florid cemento-osseous dysplasia
    • Other cemento-osseous dysplasia
• Cherubism
• Central giant cell granuloma
• Aneurysmal bone cyst
• Solitary bone cyst (traumatic, simple, hemorrhagic bone cyst).

Fibrous Dysplasia: Fibrous dysplasia (FD) is a benign intra-medullary genetic disorder of bone that may affect single (monostotic: MFD) or multiple bones (polyostotic: PFD).

Fibrous dysplasia Pathogenesis:

• Fibrous dysplasia is a disorder in the remodeling process of primordial bone to mature bone. Immature, coarse, bony trabeculae are embedded in a dysplastic fibrous tissue matrix with insufficient mineralization.
• There is a gene mutation in the 20q chromosome, and all cell derivatives of the mutant gene manifest dysplastic features.
• McCune-Albright syndrome (MAS) may have a component of fibrous dysplasia. MAS is an intermittent type of syndrome described as a triad of polyostotic, hyper-pigmentation (cafe-au-lait spots), and multiple endocrinopathies like sexual precocity in females.
• Maxillary involvement is more common than mandibular involvement. Craniofacial FD describes FD affecting the maxilla, maxillary sinus, zygoma, sphenoid, temporal, orbital, nasal, frontal, and occipital bones. FD is unilateral and rarely occurs bilaterally.

Fibrous dysplasia Clinical Features:

• Fibrous dysplasia arises within the first or second decades of life. It is slow-growing and causes asymptomatic expansion of the affected bone.
• The degree of deformity depends on the site and extent of bone involvement, (mono or polyostotic type). Facial asymmetry is also present.
• Rapid expansion is rare. There is an acceleration period following the slow growth leading to facial deformity and nerve compression.
• The active growth phase typically slows down during puberty or after skeletal maturation.
• The head is the most common site in monostotic form, and in polyostotic form femur, tibia, and pelvis are involved.
• The prognosis is good, and recurrence following treatment is rare.

Fibrous dysplasia Radiographic Diagnosis:

• The various imaging techniques include:
  • Conventional panoramic technique
  • Computed tomography
  • Magnetic resonance imaging (MRI)
  • Scintigraphy
• The developmental stage and the quantity of bone deposition in the affected site determine the radiographic pattern of the FD. In the conventional tomographic view, well-defined radiolucency represents the early stage of lesion whereas radiodense sclerotic pattern denotes the mature stage of FD.
• The pathognomonic ground-glass or orange peel image pattern reveals the merged boundaries between the fibrous dysplastic bone and the unaffected bone.

Fibrous dysplasia Distinctive Radiographic Features:

• Loss of lamina dura of the teeth in the affected region of the maxilla and mandible.
• Displacement of the inferior alveolar canal in an upward direction.
• Arrangement of abnormal trabeculae in a swirling pattern resembling thumbprint.

Fibrous dysplasia Differential Diagnosis: Nonossifying fibroma, low-grade osteosarcoma, simple bone cyst.

Fibrous dysplasia Management:

• For polyostotic forms, referral to an endocrinologist is mandatory for the diagnosis and management of endocrine abnormalities.
• Bisphosphonates (pamidronate) is used extensively for treating patients with polyostotic disease.
• Surgical resection.

 

Odontogenic And Nonodontogenic Tumors Viva Voce

Question 1. What is fibroma?
Answer:

• Fibromas are sessile, firm growths occurring on the oral mucosal surface. Histologically they are composed of inflamed fibrous and granulation tissues.
• The primary etiological factor is chronic trauma or irritants.

Question 2. What is epulis?
Answer: Epulis refers to small sessile or pedunculated growths occurring on the gingiva as a response to inflammatory reactions for chronic trauma or irritants.

Question 3. What is epulis fissuratum?
Answer: Epulis fissuratum is the overgrowth of alveolar mucosa associated with the periphery of ill-fitting dentures.

Question 4. What is a pulp polyp?
Answer:

• Pulp polyp is the proliferation of pulpal connective tissue through substantial pulpal exposure and fills the cavity with decayed teeth.
• It is a bright red mushroom¬shaped growth with a connecting stalk to the pulp cavity.
• They bleed on palpation but are asymptomatic due to the presence of fewer nerve endings.

Question 5. What is denture papilloma?
Answer:

• It is a hyperplastic lesion that develops on the hard palate due to chronic denture irritation. It is also known as denture papillomatosis and palatal papillary hyperplasia.
• It is very common for denture wearers to use maxillary dentures with suction chambers or cut on the palatal surface of the denture for retention.
• They are usually excised or removed by electrocautery, cryosurgery or laser surgery.
• Very rarely occurs in individuals without wearing dentures.

Question 6. What is pregnancy epulis
(or)
pregnancy tumor?
Answer:

• It is a pedunculated hemorrhagic nodule seen in the gingiva of pregnant women in response to chronic irritation caused by overhanging restorations, calculi, or sharp margins of intraoral appliances.
• It is the exaggerated response of gingiva to local irritants due to increased levels of circulating hormone estrogens.
• It has increased prevalence toward the end of pregnancy and shrinks after delivery.

Question 7. What is hamartoma?
Answer:

• Greek word hamartia = fault (or) defect, and oma=tumor gives rise to hamartoma.
• It is a benign (noncancerous) tumor-like malformation; that consists of tissues that are specific to that site, but growing as a disorgani¬zed mass. It is considered as a developmental error.

Question 8. What is teratoma?
Answer:

• Teratomas are germ cell tumors comprising cells derived from all three germ layers. It may be benign, well-differentiated cystic lesions or solid and malignant.
• The findings of various structures like teeth, tissue, hair, and skin in these tumors are characteristic.

Question 9. What is tuberous sclerosis?
Answer:

• It is an inherited disorder characterized by seizure and mental retardation due to neuronal deformity in the central nervous system.
• Fine wart-like lesions known as adenoma sebaceous occur in a butterfly distribution over the cheek and forehead. Pitted enamel hypoplasia is also a common finding.

Question 10. What is Cowden syndrome (multiple hamartomatous neoplasia syndrome)?
Answer:

• There is a hamartomatous involvement of many organs with a potential for neoplastic transformation.
• The presence of numerous papules and papillomatosis gives a cobblestone appearance to the oral mucosa. It is autosomal dominant.

Question 11. What are xanthomas?
Answer: Xanthomas are localized deposition of lipoprotein in the skin, subcutaneous tissue, and tendons. They are associated with vascular diseases and internal malignancies.

Odontogenic And Nonodontogenic Tumors Highlights

• A tumor is a nonspecific term and only refers to mass. A tumor may be benign, or a malignant growth originating either from the hard or soft tissue of the oral cavity.
• Odontogenic tumors develop from the cells or tissues that initiate tooth development. Their clinical and pathohistological characters are different.
• The tumors may exhibit hamar- tomato proliferation, a nonaggressive benign course, or an aggressive and malignant behavior. Nonodontogenic tumors of the jaw are of soft tissue origin like epithelium, connective tissue components, mucosa, and muscles. They are either benign or malignant.