Fibro-osseous lesions

1. FIBROUS DYSPLASIA
PRESENTERS: SIMON MPHANDE
KASAMBA MWEEMBA
5TH YEAR MBCHB - CBU(SOM)

2. OUTLINE
 INTRODUCTION
 EPIDEMIOLOGY
 ETIOLOGY
 CLASSIFICATION
 CLINICAL FEATURES
 INVESTIGATIONS
 DIFFERENTIAL DIAGNOSIS
 MANAGEMENT
 PROGNOSIS
 CONCLUSION

3. INTRODUCTION
 Fibrous dysplasia is a benign skeletal developmental anomaly
characterized by presence of fibrous connective tissue with a
characteristic whorled pattern and containing trabeculae of
immature non lamellar bone.
 Fibro-osseous lesions are a diverse group of processes that
are characterized by replacement of normal bone by
fibroblasts and collagen fibres containing a newly formed
mineralized product
 The commonly included fibro-osseous lessions are fibrous
dysplasia , cemento-osseous dysplasia and ossifying fibroma.

4. WHO Classification of Fibro-Osseous
Lesions 2005
1. Ossifying fibroma
2. Fibrous dysplasia
3. Osseous Dysplasia
4. Central giant cell granuloma
5. Cherubism
6. Aneurysmal Bone cyst
7. Solitary bone cyst

5. EPIDEMIOLOGY
 Fibrous Dysplasia affects males and females in equally
Initial symptoms manifest age 3-15 years
Not a hereditary disease
The monostatic form is more common than the
polyostotic form according to some reports by a ratio of
4:1
Mild cases of the disorder may go undiagnosed, making
it difficult to determine the true frequency of FD in the
population.

6. ETIOLOGY
 Fibrous dysplasia is not a hereditary disease in nature and
the underlying cause is not fully understood.
 However, it is associated with a gene mutation on a specific
gene GNAS1 (guanine nucleotide binding protein, alpha
stimulating active polypeptide).
 This gene affects how certain body cells grow, divide and
die, including bone cells.
 This results in the over production in the cAMP which has
effect on differentiation of osteoblasts, melanocytes and
endocrine cells.
 The clinical severity of the condition depend on the point in
time during fetal or postnatal life that the mutation of the
gene occurs.

7. JAFFE-LICHTENSTEIN
SYNDROME
McCUNE ALBRIGHT
SYNDROME

12. CLASSIFICATION
 Based on the number of boned involved
1. Monostatic- involves one bone only
2. Polyostotic –involes two or more bones
 The polyostotic fibrious dysplasia is associated with Three
syndromes ; McCune-Albright syndrome and Jaffe-lichtestein
syndrome and mazabraud syndrome.

13. MONOSTOTIC FIBROUS DYSPLASIA
70-80% of fibrous dysplasia involving one bone only
 Painless swelling which may involve labial or buccal plate.
 It is diagnosed most often during the second and third decade of life.
 Males and females are affected equally.
 Commonly involved sites are ; ribs, tibia, femur, cranial facial bones and
the humerus.
 The maxilla if affected more often than the mandible.
 The growth is generally slow and its common for the patient to be
aware of the condition after several years before seeking medical
evaluation
 Maxillary lesions often involve the adjacent bones such as the
zygomatic bones, sphenoid and occipital bones.
 Adjacent teeth may be displaced by mass but usually remain firm .

15. Involvement of the mandible
 Expansion of the lingual and buccal plates and also bulging of
the lower border
 Superior displacement of the inferior alveolar canal
 Narrowing of the periodontal ligament space.

17. POLYOSTOTIC FIBROUS DYSPLASIA
 20-30% of fibrous dysplasia Involving two or more bones
 The mutation occurs in skeletal progenitor cells at later stages of embryonic
development.
 Less common and more severe, occurring unilaterally.
 Site ; femur, tibia, pelvis, ribs, skull, facial bones, upper extremity, lumbar and
cervical.
 Pain is involved
 Spontaneous fractures are common with facial asymmetry and multiple bone
dysplasia
 Age – before ten years
 The polyostotic fibrious dysplasia is associated with three syndromes ;
McCune-Albright syndrome and Jaffe-lichtestein syndrome and mazabraud
syndrome.

25. CLINICAL FEATURES
 Local pain ( polyostotic) or a painless lump (monostotic)
 Problems with eating due to gaps developing between teeth.
 Expansion of craniofacial lesions may lead to progressive facial deformity.
 Swelling in the Jaw
 Abnormal pigmentation due to increased melanin in basal cells of the epidermis
seen in ipsilateral side of bone lesion.
 Hyper functioning of the endocrine causing endocrinopathies eg sexual
precosity.
 Problems with hearing if the ear canal narrows
 Visual disturbances if the optic nerve is compressed
 Long bones prone to fracture if affected ( pathological fractures).

26. INVESTIGATIONS
 Clinical History and Examination
supportive Investigations
 Full Blood Count and Differential Count
 Crossmatch
 Liver function tests
 Serum Calcium levels
 Basal metabolic rate
Diagnostic investigations
 X- ray
 Magnetic Resonance Imaging
 Computerized Tomographic Scan
 Bone isotope scan ( to determine affected areas of the body)
 Bone biopsy

28. RADIOLOGICAL FEATURES
 These are extremely variable because the lesions keeps on maturing, features
depends on the degree of calcification and stage of tumor
early stage ; small unilcular/ large multilocular radioluscent appearance.
mid stage; moderate radiopaque appearance. Molten appearance.
late stage; complete radiopaque lesion, ground grass appearance.
Other features: cortical thinning, separated root of teeth, bony expansion.
Note : FD lesions are not well defined, the blend into adjacent bones-R/O
ossifying fibroma , lesions well defined.

30. HISTOLOGICAL FEATURES
MONOSTOTIC
 Proliferating fibroblasts in a compact stroma of interlacing collagen fibres.
 Irregular bony trabeculae scattered throughout the lesion which are also
known as C-shaped or Chinese character shaped
 Trabeculae usually coarse woven bone
 No definite pattern
POLYOSTOTIC
 Lesions rich in spindle shaped fibroblasts with a swirled appearance within
the narrow space
 Islands of cartilaginous tissue within lesions
 Affected bones may have cystic lesions lined by multinucleated giant cells.

33. DIFFERENTIAL DIAGNOSIS
 Ossifying Fibroma
 Periapical Cement- Osseous Dysplasia
 Focal Cement-Osseous Dysplasia
 Florid Cement-Osseous Dysplasia
 Paget`s Disease
 Osteosarcoma
 Hyperparathyroidism
 Chronic Osteomyelitis

34. MANAGEMENT
CONSERVATIVE
To prevent deformity
MEDICAL
 Bisphosphonates help prevent bone loss by decreasing the activity
of cells that normally dissolve bone.
 Some examples of bisphosphonates are risedronate, ibandronate.
 Studies show that these drugs strengthen bones affected by
fibrous dysplasia and may relieve bone pain.
 Vitamin B, Better mineralization of the bone.

35.  SURGICAL
 Since it may affect various areas of the body treatment is best
delivered at a specialist centre were a multidisciplinary team
approach can be taken.
 Surgery is indicated for confirmatory biopsy, correction of
deformity and prevention of pathological fractures
 This team should comprise of craniofacial surgeons,
neurosurgeons, ENT surgeons, ophthalmologists, dentists and
orthodontist.
 Surgery to remove the fibrous tissue is difficult due to
thickness and is not always successful.

36.  However if bone growth is affecting function, particularly
vision, surgery may be carried out earlier in childhood.
 If the skull is involved surgery to re-shape the skull may take
place in several stages.
 Many cases, disease tends to stabilize and stops enlarging
when skeletal maturation is reached.

37. MALIGNANT TRANSFORMATION
 0.4 – 4%
 Osteosarcoma
 Fibrosarcoma
 Chondrosarcoma
 28% seen in radiated. Therefore, Radiotherapy is
contraindicated
 The cases are high in women due to the high levels of
estrogen as compared to men.

38. PROGNOSIS
 The prognosis is usually good
 Although bad outcomes occur more frequently among young
patients
 Bad outcomes may also be seen in patients with polyostotic
forms of Fibrous Dysplasia

39. CONCLUSION
 Fibrous Dysplasia is a lesion of bone commonly affecting the
younger age group.
 It shows similarities with other fibro osseous lesions clinically,
radiologically and histopathologically.
 Hence thorough knowledge about these lesions is necessary
for proper diagnosis and treatment plan.

40. REFERENCES
 Neville B.W. (2016) Oral and Maxillofacial Pathology, 4TH
Edition, Elservier Canada.
 Anil G. (2014) Textbook of oral medicine 4th Edition , Jaypee
brothers medical publisher
 Rajendran .R. (2020) Shafer’s textbook of oral pathology, 9th
Edition Elservier India.

41. THANK
YOU