Bone Diseases II Flashcards
What are the most common benign cemento-osseus lesions?
Fibrous dysplasia
Cemento-osseous dysplasias Sub-types: Periapical cemental
Focal cemento-osseous
Florid cemento-osseous
Cemento-ossifying fibroma Sub-types: Conventional Juvenile Active
What is fibrous dysplasia?
A benign non-neoplastic, tumour-like, developmental defect in bone formation
It is caused by a fibrous proliferation forming disorderly malformed woven bone which is structurally weak.
Where is fibrous dysplasia most commonly found?
Ribs
Femur
Tibia
Pelvis
Craniofacial
What age is fibrous dysplasia most commonly seen?
Onset typically seen in childhood - adolescence
What are the clinical features of fibrous dysplasia?
Single or multiple bony lesions
Slow growing
Painless
Often quiesces at puberty
Genetics: GNAS I gene chromosome 20q13.1-2
What are the types of fibrous dysplasia?
Monostotic (70%) craniofacial (25%)
Polyostotic (25%) craniofacial (50%)
McCune-Albright Syndrome (3%) Endocrine abnormalities
What are the symptoms of fibrous dysplasia?
Painless swelling
Facial asymmetry
Malocclusion – displaced teeth
Headache
Hearing loss
Clinical labs: elevated alkaline phosphatase
What are the radiographic symptoms of fibrous dysplasia
Early lesions are radiolucent/mottled
GROUND GLASS APPEARANCE
Diffuse and poorly dilineated
Cortical expansion
Narrow PDL
Obscure lamina dura
What does fibrous dysplasia look like histologically?
Woven bone
Irregular trabeculae “chinese characters”
Fibrous stroma
No osteoblastic lining
Blends into normal bone - no capsule
Maturation into lamellar bone
What complications can arise from fibrous dysplasia?
Debilitating deformities
Aesthetic/psychosocial concerns
Malocclusion
Pathologic fractures
Cranial nerve and orbital involvement
Malignant degeneration
What causes malignant degneeration of areas with fibrous dysplasia?
- rare (< 1%)
- osteosarcoma
- avoid radiation therapy
How is fibrous dysplasia managed?
May not require treatment; conservative management is best.
Stabilizes with skeletal maturity
Diffuse involvement precludes excision
Cosmetic and functional deformity
Surgical recontouring/decompression
Regrowth (25-50% - younger patients)
What causes fibrous dysplasia?
This is caused by mutation in GNAS1 gene G protein increasing cAMP production in cells.
If it occurs early in development this results in a more pluripotent stem cell getting ti and thus a systemic condition results (McCune Albright syndrome) and if it occurs later in development it can become monostotic. If at an intermediate stage polyostotic.
What is periapical cemento-osseus dysplasia?
A benign non-neoplastic dysplastic process
Who typically gets periapical cemento-osseus dysplasia?
Incidence: relatively common
Age: middle age (30 – 50 years)
Gender: female > male (14:1)
Race: black
Where does periapical cemento-osseus dysplasia typically occur?
Mandible anteriorly in the periapical area.
What are the clinical symptoms of periapical cemento-osseus dysplasia?
Asymptomatic, vital teeth, non-expansible
What are the common radiographic findings of periapical cemento-osseus dysplasia?
Multiple, circumscribed apical radiolucencies. < 1cm
Variable in radiopacity based on maturation
Non-expansile
Teeth are vital.
What are the histological features of periapical cementoosseus dysplasia?
Spindled fibrous
stroma
Cementum calcified
matrix
Osseous calcified
matrix
Maturation
No inflammation
How is periapical cemento-osseus dysplasia managed?
Clinical – radiographic diagnosis
Benign self limiting process
No progressive growth
No treatment required
Prognosis: excellent
Avoid unnecessary endodontic therapy,
surgery or extractions
Who commonly gets focal cemento-osseus dysplasia?
4-5th decade
Most commonly in females
Caucasians
What causes focal cemento-osseus dysplasia?
Non-neoplastic - disordered growth of cementum and bone
What are the clinical features of focal cemento-osseus dysplasia?
Most common site: Posterior mandible
Asymptomatic
Solitary
Edentulous areas
Size: < 1.5 cm
What are the radiographic features of focal cemento-osseus dysplasia?
Mixed radiolucent - opaque well defined borders
What are the histological features of focal cemento-osseus dysplasia?
Benign fibro-osseus lesion
Cellular spindled fibrosis
Collagen fibers
Globular cementum matrix material
Woven osseous matrix material
Vascular channels
How is focal cemento-osseus dysplasia treated?
Curettage (Biopsy)
Watching and following up periodically.
What is the prognosis of focal cemento-osseus dysplasia like?
Excellent prognosis (limited growth potential)
What is florid cemento-osseus dysplasia?
Benign non-neoplastic dysplastic process
What are the radiographic findings for florid cemento-osseus dysplasia?
Irregular lobular dense
radiopacities
Mixed radiolucent and
radiopaque areas
Diffuse involvement
of maxilla and mandible
Bilateral
Symmetrical
What are the histolopathologic findings of florid cemento-osseus dysplasia?
Fibroblastic proliferation
Dense sclerotic calcific masses
Cementum matrix
Woven bone
Inflammatory infiltrate
Simple bone cysts
How is florid cemento-osseus dysplasia managed?
Benign self-limiting process
No treatment required
Potential for significant complications
Avoid exposure of calcific masses
Maintenance of dentition
Chronic osteomyelitis
– pain, fistulae, dehiscence, sequestration
Traumatic bone cysts
What is a cementoblastoma?
An odontogenic tumour that forms a mass of cementum or cementum like tissue and is continuous with the tooth root.
Can be very destructive of tissue
Which teeth are often affected by cementoblastomas?
Usually a mandibular premolar or first molar
What are the clinical features of a cementoblastoma?
Tender, sometimes painful swelling
Located on the buccal and lingual/palatal aspect of the alveolus
Who typically gets a cementoblastoma?
Under 30 years of age
M:F 1.2:1
Which tooth is most commonly affected by a cementoblastoma?
Mandibular 1st molar
80% of them are in the mandible
What are the radiographic features of a cementoblastoma?
Radiopaque mass with a thin radiolucent rim
attached to the roots of a tooth
Tooth resorption, loss of root outline, and
obliteration of the periodontal ligament
space
What are the histological features of a cementoblastoma?
Sheets or trabeculae of cementum-like calcified tissue with variably prominent reversal lines, sometimes with a pagetoid appearance
How is cementoblastoma treated?
Surgery
Recurrence 35 - 60%
How are odontogenic tumours classified?
Based on similarity between tumours and various stages of tooth development
- Odontogenic epithelium without odontogenic ectomesenchyme
- Odontogenic epithelium with odontogenic
ectomesenchyme, with or without dental hard tissue formation - Odontogenic ectomesenchyme with or
without included odontogenic epithelium
What benign tumours fall under the category of odontogenic epithelium without odontogenic ectomesenchyme?
Ameloblastoma
Squamous odontogenic tumour
Calcifying epithelial odontogenic
tumour (Pindborg Tumour)
What benign tumours fall under the category of odontogenic epithelium without odontogenic ectomesenchyme +/- dental hard tissue?
Ameloblastic fibroma
Ameloblastic fibro-dentinoma
Ameloblastic fibro-odontome
Adenomatoid odontogenic tumour
Calcifying odontogenic cyst
Complex odontome
Compound odontome
What benign tumours fall under the category of odontogenic ectomesenchyme +/- odontogenic epithelium?
Odontogenic fibroma
Myxoma [myxofibroma]
Benign cementoblastoma (‘true’ cementoma)
Which odontogenic tumours are malignant?
Clear cell odontogenic carcinoma
Malignant ameloblastoma
Primary intra-osseus carcinoma
Malignant variants of other odontogenic epithelial tumours
Malignant changes in odontogenic cysts
What are the clinical features of ameloblastoma?
Slow growing, polycystic or monocystic
Who typically gets ameloblastoma?
More males after the age of 40
What is an osteoma?
A reactive, developmental (non-neoplastic) bone forming tumour
Where is an osteoma typically found?
Craniofacial bones: Skull and paranasal sinuses
What are the symptoms of an osteoma?
Often a solitary, exophytic mass of dense bone arising from periosteal or endosteal surface.
Often asymptomatic and is a non-aggressive tumour with no malignant transformation
What is an osteosarcoma?
Malignant mesenchymal neoplasm
Osteoid production by tumor cells
Most common primary bone malignancy
What is the most common age of onset of an osteosarcoma? Is it male or female dominant?
2nd decade of life
More common in males Male:Female 1.6:1
What are the most common sites for an osteosarcoma?
Metaphysis of long bones
Distal femus, proximal tibia, humerus
What could potentially cause osteosarcoma?
Could be primary (most common primary bone malignancy)
Secondary to:
Paget’s disease of bone
Fibrous dysplasia
Irradiation
Retinoblastoma
– tumor suppressor gene (13q14)
Osteochondromatosis
Chronic osteomyelitis
Where on the head and neck is osteosarcome most commonly seen?
Incidence: rare in the jaws
6-8% occur in gnathic skeleton
Age: 3-4th decade (mean age 33 years)
Gender: male > female
Site:
mandible = maxilla, paranasal sinuses, skull
What are the typical symptoms of osteosarcoma of head and neck?
Painful swelling
Parasthesia
Loose teeth
What are the radiographic findings of osteosarcoma?
Mixed radiolucent/radiopaque
Destructive
Poorly defined infiltrative borders
Sunburst pattern in 25%
Symmetric widening of the PDL
Calcification above the level of the alveolar crest
Spiking root resorption
What are the histological features of osteosarcoma?
Pleomorphic malignant mesenchymal cells
Spindled to polygonal morphology
Osteoid production
Osteoblastic, chondroblastic, fibroblastic types
Atypical mitotic figures
Necrosis
Gnathic tumors are better differentiated
What blood findings would be seen in osteosarcomas?
Elevated alkaline phosphatase
How is osteosarcoma treated?
Radical surgery
Chemotherapy
Radiation therapy
What is the prognosis of osteosarcoma like?
It is an aggressive neoplasm with 30 - 50% survival
Local recurrence rate of 70%
Metastasis (6-50%)
Lung brain and lymph nodes
Mortality is persistent with local/regional disease
Which tumours metastasize commonly to the bone?
Carcinomas of the:
Breast
Prostate
Lung
Kidney
Thyroid
Which bones do tumours typically metastasize to?
Hematogenous spread to the vertebral column, pellvis, ribs and skull
How do metastatic tumours affect bone?
Can be osteolytic or osteoblastic (cytokine mediated)
What is the prognosis like in metastatic tumours?
Poor
How common are metastatic tumours to the jaws?
Uncommon (16%)
Where on the face do metastatic tumours metastasize to?
Mandible typically (80%)
What are the symptoms of metastatic cancer to the jaws?
Painful mass - swelling
Loose teeth
Parasthesia
What are the radiographic findigns of metastatic tumours to the jaws?
Osteolytic: ill defined destructive radiolucency
Osteoblastic: radiopaque or mixed lesion
May simulate periapical or periodontal disease
What are the histological features of metastatic tumours to the jaws?
Infiltrating nests and cords of pleomorphic epithelial cells with fibrous stroma
What is the prognosis like in metastatic tumours ot the jaws?
Poor prognosis for widely disseminated disease. Unlikely to survive 1 year.
