fibro-osseous lesions of bones-FIBROUS DYSPLASIA

FIBROUS DYSPLASIA: 

FIBROUS DYSPLASIA Dr Khin Soe B.D.S,M.D.Sc Assistant Lecturer, Department of Oral Medicine and Oral Pathology

Fibro-osseous lesions: 

Fibro-osseous lesions replacement of normal bone by cellular fibrous tissue within which varying amounts of predominantly woven bone and acellular islands of mineralized tissue develop

Fibrous dysplasia: 

Fibrous dysplasia

PowerPoint Presentation: 

Benign fibro- osseous condition involving one or more bones of the cranial and extracranial skeleton, consists of non-encapsulated lesions which show replacement of normal bone by cellular fibrous tissues (Edwards 1984) Originally introduced by Lichtenstein in 1938 One of the most perplexing diseases of osseous tissues. A lesion of unknown aetiology, uncertain pathogenesis and diverse histopathology

FIBROUS DYSPLASIA: 

FIBROUS DYSPLASIA

Fibrous dysplasia: 

Fibrous dysplasia Non- neoplastic lesion of bone in which fibro-osseous lesions of bone replace the trabecular bone, altering its size and shape

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Involving only one bone (A) Monostotic form Juvenile Adult (B) Polyostotic form (Involvement of two or more bones) Sub classified into (i) Jaffe-Lichtenstein syndrome - Bone involvement + café-au-lait pigmentation (ii) Mc Cune-Albright syndrome - Polyostotic F.D + café-au-lait pigmentation + multiple endocrinopathies such as sexual (precocity, pituitary adenoma; hyperthyroidism) (café-au-lait = coffee with milk; pale brown patches on the skin) (iii) Craniofacial form confined to bones of the craniofacial complex Clinical Types

Fibrous dysplasia affecting the right side of mandible: 

Fibrous dysplasia affecting the right side of mandible

Typical buccal expansion: 

Typical buccal expansion

Skin pigmentation in Albright’s syndrome: 

Skin pigmentation in Albright’s syndrome

Polyostotic form (i) Jaffe-Lichtenstein syndrome: 

Polyostotic form (i) Jaffe-Lichtenstein syndrome

FIBROUS DYSPLASIA: 

FIBROUS DYSPLASIA

(A) Monostotic Fibrous Dysplasia: 

(A) Monostotic Fibrous Dysplasia Less severe than polyostotic form AETIOLOGY Exact aetiology unknown Possible aetiologies (1) Aberrant actively in the forming mesenchymal tissues (2) Local infection (or) trauma (3) Reparative reaction on the part of the bone to any injuries (4) Autosomal recessive disorder Not related to polyostotic form (mostly accepted)

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CLINICAL FEATURES More common in children and young adults Painless swelling (or) bulging of the jaw Buccal plate > Lingual plate Mandible → Protuberant excrescence of inferior border (abnormal outgrowth) → Due to progressive expansile nature → Tipping (or) displacement of teeth; malalignment

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Maxilla → Bulging of canine fossa (or) extreme prominence of zygomatic process causing marked facial deformity → Extension to maxillary sinus, zygomatic process, floor of the orbit and even towards base of the skull Mandible and maxilla → severe malocclusion (+)

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Buccal expansion of maxilla

FIBROUS DYSPLASIA: 

FIBROUS DYSPLASIA

expansive radiopacity in the left maxillary sinus in fibrous dysplasia: 

expansive radiopacity in the left maxillary sinus in fibrous dysplasia

Water’s view in same patient: 

Water’s view in same patient

Orange peel appearance: 

Orange peel appearance

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RADIOGRAPHIC FEATURES Three basic Patterns: Unilocular (or) multilocular radiolucency with well-circumscribed border containing bony trabeculae network Similar to (A) except ↑ ed trabeculation leading to more opaque and typically "mottled' appearance Area of reduced radiopacity with fine orange-peel (or) thumb-print (or) ground glass appearance with egg-shell thin cortex of expanded bone (not circumscribed and blends into adjacent normal bone)

FIBROUS DYSPLASIA: 

FIBROUS DYSPLASIA

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Key feature Margins merge imperceptibly with surrounding normal bone and that limits of lesions difficult to define Severe resorption of roots

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HISTOLOGICAL FEATURES Loose cellular fibrous connective tissues stroma with proliferating fibroblasts Scattered irregular slender trabeculae ( C-shaped or Chinese character-shaped ) Loose foci of giant cells

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TREATMENT AND PROGNOSIS Self-limiting Surgical removal → Conservative removal rather than radical approach (most of the cases) Not well-circumscribed lesions → Block resected if treated by radiation → Malignant transformation (+) (Osteosarcoma) (Mock and Rosen 1986)

(B) Polyostotic Fibrous Dysplasia: 

(B) Polyostotic Fibrous Dysplasia Firstly recognized by Weil in 1922 and specifically described by Albright CLINICAL FEATURES ♀ > ♂ (3:1) 50% of the cases → head and neck involvement (+) Aching recurrent bone pain (+) Bones of face and skull involved → Facial asymmetry (+) Clavicles, pelvic bone, scapulae, long bones, meta carpals and meta tarsals (+)

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Leg length discrepancy is very common as a result of involvement of upper portion of the femur ( Hockey stick deformity ) Skin (trunk and thighs) → Café-au-lait pigmentation (+) ♀ → precocious puberty (sometimes beginning at the age of 2 (or) 3 years (or) even younger and vaginal bleeding is common manifestation) Mandible > Maxilla Due to endocrine disturbance → Time of eruption altered Pituitary, thyroid, parathyroid and ovary → Disturbance (+)

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RADIOGRAPHIC FEATURES Rarefication (decrease in density) of medullary portion of bone Irregular trabeculation with expanded, thin cortical bone

Late stage of fibrous dysplasia: 

Late stage of fibrous dysplasia

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LABORATORY FINDING Moderately elevated BMR Premature secretion of pituitary FSH (Follicle Stimulating Hormone)

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HISTOLOGY FEATURES Fibrous connective tissues stroma within which numerous trabeculae of woven bone Large multinucleated giant cells

FIBROUS DYSPLASIA: 

FIBROUS DYSPLASIA

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TREATMENT AND PROGNOSIS Mild case → Surgery Prognosis → depend upon degree of involvement of skeleton Radiation → Subsequent development of radiation-included sarcoma [Craniofacial F.D (involvement of zygoma, sphenoid, occiput) → Long term follow up] Careful correlation between clinical, histopathological and radiographic features Rule out serum calcium, alkaline phosphatase and parathyroid hormone

behaviour: 

behaviour A few cases of malignant transformation of fibrous dysplasia have been reported, usually to fibrosarcoma , some of which have followed radiotherapy. However, the lesions of fibrous dysplasia are not radiosensitive and radiotherapy, which may increase the risk of malignant change, is not an acceptable treatment.

PowerPoint Presentation: 

The majority of cases are treated by conservative surgical removal of sufficient of the lesion to reduce deformity. The lesions tend to expand mainly during the period of active skeletal growth and become quiescent in adult life.

Key points - Fibrous dysplasia of the jaws: 

Key points - Fibrous dysplasia of the jaws · more common in maxilla than mandible · fusiform bony expansion; maxillary lesions also expand into sinus · radiographic features vary depending on amount of bone formed within lesion

fusiform expansion: 

fusiform expansion

PowerPoint Presentation: 

· margins of lesion merge with surrounding normal bone · delicate trabeculae of woven bone in cellular or collagenous fibrous tissue · expansion usually stops with skeletal maturation · remodelling of woven to lamellar bone may occur with increasing age

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Thank you