OAOL Diseases of Bones and Joints PDF

Presentation Title Diseases of bones & joints Classification of diseases of bone  A. DEVELOPMENTAL DISEASES: – Cherubism – Osteopetrosis – Osteogenesis imperfecta – Cleidocranial dysplasia B. ENDOCRINAL DISEASES: – Hyperparathyroidism C. IDIOPATHIC DISEASES:...

Presentation Title Diseases of bones & joints Classification of diseases of bone  A. DEVELOPMENTAL DISEASES: – Cherubism – Osteopetrosis – Osteogenesis imperfecta – Cleidocranial dysplasia B. ENDOCRINAL DISEASES: – Hyperparathyroidism C. IDIOPATHIC DISEASES: – Idiopathic osteosclerosis – Massive osteolysis – Langerhan’s cell disease (Histiocytosis-X) – Paget’s disease  D. REACTIVE DISEASES: – Giant cell lesion of bone – Aneurysmal bone cyst – Simple / Traumatic bone cyst E. FIBRO-OSSEOUS LESIONS: – (i) Non-neoplastic lesions - Fibrous dysplasia Cemento-osseous dysplasia – (ii) Neoplasms – Ossifying fibroma  F. INFLAMMATORY DISEASES: - – (i) Specific: Tuberculosis Actinomycosis – (ii) Non specific Osteomyelitis Dry socket Periapical cyst / abscess / granuloma Osteoradionecrosis  G. NEOPLASTIC DISEASES: - – (i) Benign: Osteoma Osteoid osteoma & osteoblastoma Chondroma Chondromyxoid fibroma – (ii) Malignant: Osteosarcoma Ewing’s sarcoma Chondrosarcoma  Developmental disorders 1. CHERUBISM 2. OSTEOPETROSIS 3. OSTEOGENESIS IMPERFECTA 4. CLEIODOCRANIAL DYSPLASIA.  CHERUBISM Rare developmental jaw condition Transmitted as an autosomal dominant trait Bilateral occurrence Child appears as a plump cheeked angels called “Cherub” Jaw lesion remit spontaneously when the child reaches puberty, leaving some facial deformity and malocclusion but reason for this remission is still unknown. The appearance of people with the disorder is caused by a loss of bone, which the body replaces with excessive amounts of fibrous tissue Pathogenesis Due to mutation in SH3BP2 gene mapped to chromosome 4p16. Mutation were identified in the SH3BP2 gene increase the activity of osteoclasts and osteoblasts during normal tooth eruption.  HISTOLOGICAL FEATURES Normal bone is partly replaced by pathologic tissue. Numerous multinucleated giant cells and vascular spaces within a fibrous connective tissue stroma. Diffuse spindled mononuclear cells, fresh haemorrhage, and eosinophilic fibrinous material Eosinophilic perivascular cuffing is seen. Multinucleated giant cells are positive for tartrate resistant acid phosphatase which is characteristic of osteoclasts.  OSTEOPETROSIS Synonyms  Albers - Schonberg Disease  Marble bone disease  Osteosclerosis fragilis generalisata Rare disease characterized by excessive density of all bones with obliteration of marrow cavities. Cause: Defective remodelling due to failure of osteoclastic function. Osteoclast number is often increased – but no bone is resorbed. Bone has poor mechanical properties HISTOLOGICAL FEATURES: Failure of osteoclasts to resorb skeletal tissue. Abnormal bone formation Tortuous lamellar trabeculae replacing cancellous bone Globular amorphous bone deposition in marrow spaces Osteoclasts may be increased, normal or decreased, but there is no evidence of functional osteoclast as Howship’s lacunae are not visible.  Osteogenesis Imperfecta Synonyms Brittle bones, Fragilitas ossium Osteopsathyrosis Lobstein’s disease Developmental, inherited bone disorder, showing both autosomal dominant and recessive pattern. Connective tissue disorder in which bone fragility is seen.  Basic abnormality is a genetic defect in collagen maturation / synthesis of type I collagen. Mutation of genes – COLIA1 – chromosome 17 COLIA2 – chromosome 7 It is characterized by impairment of collagen maturation. Collagen forms a major portion of bone, dentine, sclerae, ligaments, and skin, Osteogenesis Imperfecta demonstrates a variety of changes that involves these sites. HISTOLOGICAL FEATURES: - Abnormal collagen synthesis by abnormal osteoblasts. Mass of cortical and cancellous bone is abnormal and greatly reduced. Cortical bone is extremely thin while the cancellous bone is delicate and shows micro fractures. Osteoblasts are present but bone matrix synthesis is reduced, for this reason the thickness of long bone is deficient. Bone architecture remains immature throughout life.  Idiopathic diseases 1. Idiopathic osteosclerosis 2. Massive osteolysis 3. Langerhans cell disease 4. Pagets disease  PAGET’S DISEASE Also called as Osteitis deformans Characterized by abnormal resorption and deposition of bone, resulting in distortion and weakening of bone. ETIOLOGY: Unknown Inflammatory Genetic Endocrine factors Slow virus infection Positive family history Histopathology Uncontrolled alternating resorption and deposition of bone Increased osteoclastic activity in resorptive phase Osteoblastic activity with formation of osteoid rims around bone trabeculae Vascular fibrous CT replaces marrow Presence of basophilic reversal lines in bone – representing the resorptive and formative phase “Jigsaw puzzle” or “Mosaic” appearence  LANGERHANS CELL DISEASE Idiopathic disease characterized by proliferation of histiocyte like cells (Langerhans's cells), that are accompanied by varying numbers of eosinophils, lymphocytes, plasma cells & multinucleated giant cell. Believed to be a non-neoplastic process. Langerhans's cells are dendritic, mononuclear cells normally found in epidermis, mucosa, lymph nodes & bone marrow. Also known as antigen presenting cells. Histological Features Lesion shows diffuse infiltration of pale staining, mononuclear cells containing ill defined cell borders and vesicular nuclei. Darker staining eosinophils, plasma cells and lymphocytes and multinucleated giant cells also seen. Rod / racquet shaped characteristic Birbeck granules within cytoplasm of Langerhans's cells  Immunohistochemical studies are needed to confirm the diagnosis as these cells cannot be distinguished from normal histiocytes. Langerhans's cells stain positively for S-100 protein.  Reactive lesions – Central giant cell granuloma – Aneurysmal bone cyst – Traumatic bone cyst  CENTRAL GIANT CELL GRANULOMA 1st described by Jaffe – central giant cell reparative granuloma. Reparative – term is omitted. Considered to be a non neoplastic lesion. Uncommon, Benign and proliferative lesion. Extraosseous variant – Peripheral giant cell granuloma HISTOLOGICAL FEATURES: Few to large number of small / large multinucleated giant cells seen in a background of ovoid / spindle shaped mesenchymal cells. Giant cells believed to represent osteoclasts, and vary in size from few to many nuclei.(20 nuclei or more ) Foci of osteoid and newly formed bone may also be seen. Areas of haemorrhage and hemosiderin deposition seen.  ANEURYSMAL BONE CYST Primarily seen in long bones or vertebrae, and rarely in jaws. Cause and pathogenesis are not yet clear. Controversy – whether it arises de novo or occurs as a result of some “vascular accident” in a pre-existing lesion. It is an intraosseous accumulation of variable sized, blood filled spaces surrounded by cellular fibrous connective tissue often admixed with trabeculae of reactive woven bone.  Pathogenesis. It is believed to arise from: A traumatic event, vascular malformation, or neoplasm that disrupts the normal osseous hemodynamic and leads to an enlarging, hemorrhagic extravasation. HISTOPATHOLOGICAL FEATURES: Cyst cavity shows many capillaries and blood filled spaces, of various sizes separated by delicate loose connective tissue. Blood filled spaces are not lined by endothelium. Many small multinucleated giant cells and trabeculae of osteoid / woven bone cab be seen.  SIMPLE BONE CYST Solitary / Traumatic / Haemorrhagic bone cyst It is a benign, empty, or fluid containing cavity within bone that is devoid of an epithelial lining. Commonly seen in mandible, rare in maxilla. PATHOGENESIS Two theories are given: First theory – Any trauma to bone that is insufficient to cause fracture which results in intra medullary haemorrhage which fails to organize and repair clot subsequently liquefies resulting in CYST. Recent theory – osteogenic cells fail to differentiate locally and thus instead of bone, the undifferentiated cells form synovial tissue. HISTOPATHOLOGICAL FEATURES Wall shows loose fibrovascular CT. Haemorrhage and hemosiderin pigment usually present. Multinucleated giant cells scattered within the CT. Adjacent bone shows osteoclastic resorption on inner surface.  FIBRO-OSSEOUS LESIONS: – (i) Non-neoplastic lesions - Fibrous dysplasia Cemento-osseous dysplasia – (ii) Neoplasms – Ossifying fibroma  FIBROUS DYSPLASIA Condition in which normal medullary bone is gradually replaced by an abnormal fibrous connective tissue proliferation. Varying amounts of osteoid that presumably arises through metaplasia & the resultant fibro-osseous tissue is poorly formed and structurally inadequate. Condition tends to stabilize and stops growing as skeletal maturity is reached. ETIOLOGY Unknown No hereditary influence Result from mutation of GNAS 1 gene (guanine nucleotide binding protein α-stimulating activity polypeptide 1) that encodes a G protein which results in uncontrolled production of c AMP Fibrous Dysplasia Hyperfunction of endocrine organsprecocious puberty, hyperthyroidism, growth hormone and cortisol production. Increased proliferation of melanocytes large café au lait spots Histological features : Lesion shows typical irregular, shaped trabeculae of immature woven bone in a cellular, vascular stroma. Trabeculae are not connected to each other. They often assume curvilinear shape, which have been linked to Chinese script writing. Trabeculae believed to arise due to metaplasia and are not bordered by osteoblasts. Stroma is highly cellular and vascular.  Lesional bone fuses directly to normal bone at the periphery of the lesion, so that no capsule or line of demarcation is involved. Jaw & skull lesions tends to be more ossified than other counterparts in the rest of the skeleton. Some jaw lesion which rarely undergo maturation shows lamellar bone in a cellular connective tissue stroma.  CEMENTO-OSSEOUS DYSPLASIAS Commonest type of fibro-osseous lesions in head and neck region, occurring in the tooth bearing area. Believed to represent some form of reactive process. Pathogenesis: Arise in close approximation to the periodontal ligament and exhibits histopathological similarities with the structure. Hence some investigators have suggested these lesion are of periodontal ligament origin. Other investigators believe it is triggered by local factors and possibly correlated to hormonal imbalance. TYPES OF CEMENTO-OSSEOUS DYSPLASIAS Based on their clinical and radiological features, grouped into – 1.Periapical cemento-osseous dysplasia – 2.Focal cemento-osseous dysplasia – 3.Florid cemento-osseous dysplasia HISTOPATHOLOGICAL FEATURES: In early stages, lesion shows fibroblastic proliferation which may contain small areas of osteoid formation. No evidence of inflammation.  In later stages, the lesion shows increasing deposition of bone or cementum like material. In the final stages, the entire lesion may be composed of dense mineralized tissue.  OSSIFYING FIBROMA (Cementifying fibroma / Cemento-ossifying fibroma) Ossifying fibroma (OF) is a well circumscribed, sometimes encapsulated neoplasm composed of fibrous tissue containing varying amounts of calcified material. Calcified material may be bone, cementum like spheruls or a mixture of both. HISTOPATHOLOGICAL FEATURES Most tumors are well circumscribed masses composed of fibrous tissue and containing calcified material. Calcified material may be in the form of irregular trabeculae of osteoid or basophilic, globular calcifications resembling cementum. Many times both are present in the same lesion.  JUVENILE OSSIFYING FIBROMA (Aggressive ossifying fibroma) Uncommon lesion of bone. Differentiated from ossifying fibroma on the basis of age incidence, site predilection and clinical behaviour. Histologically the distinction from OF is not so clear. Two patterns recognized – trabecular and psammomatoid. HISTOPATHOLOGICAL FEATURES 1. Trabecular Juvenile ossifying fibroma: Both patterns of JOF well circumscribed but not encapsulated. Tumor composed of fibrocellular CT, areas of nuclear crowding, haemorrhage and occasional multinucleated giant cells. Mineralized component shows irregular strands of osteoid lined by plump osteoblasts.  2. PSAMMOMATOID Juvenile Ossifying Fibroma: The stroma is similar to trabecular JOF. Mineralized material is composed of concentric, lamellated and spherical ossicles. Ossicles vary in size and typically have basophilic centres with eosinophilic osteoid rims.  NEOPLASTIC DISEASES: - – (i) Benign: Osteoma Osteoid osteoma & osteoblastoma Chondroma Chondromyxoid fibroma – (ii) Malignant: Osteosarcoma Ewing’s sarcoma Chondrosarcoma  OSTEOMA Benign tumors composed of mature compact / cancellous bone. Commonly occur in craniofacial skeleton – rare in other parts of body. Palatal and mandibular tori are not considered as osteomas although they are histologically identical. TYPES OF OSTEOMA I. Depending on location: – Periosteal – Endosteal II. Depending on type of bone: – Compact – Cancellous HISTOPATHOLOGICAL FEATURES 1. Compact Osteoma: Normal looking mature compact bone with minimal marrow tissue. 2. Cancellous osteoma: Trabeculae of bone and fibrofatty marrow. Significant osteoblastic activity may be seen  OSTEOSARCOMA Osteogenic sarcoma Malignancy of mesenchymal cells that have the ability to produce osteoid or immature bone. Develops within the bone along with hematopoietic neoplasms. Majority arise from within the bone (intramedullary), some may be peripheral (juxtacortical) HISTOLOGICAL FEATURES Osteoid production by malignant mesenchymal cells. In addition to osteoid, chondroid and fibrous material also seen many times. Tumor cells may vary from spindle shaped to highly pleomorphic types. Osteosarcomas can be classified on the basis of relative amounts of chondroid / osteoid / fibers produced by tumor into: – Osteoblastic – Chondroblastic – Fibroblastic  Osteoblastic osteosarcoma containing pleomorphic malignant cells and coarse neoplastic woven bone Chondroblastic osteosarcoma with neoplastic cartilage merging with tumor bone Fibroblastic osteosarcoma containing fascicles of malignant spindle cells adjacent to deposits of neoplastic bone  CHONDROMA Benign tumors composed of mature hyaline cartilage. Common bone tumor, occurring mostly in short bones of hands and feet. Occur very rarely in jaw bones. Jaw tumors occur usually in anterior maxilla of adult patients. HISTOPATHOLOGICAL FEATURES Small hyperchromatic nuclei, and are surrounded by clear to eosinophilic cytoplasm. Cartilage is embedded in a background of abundant basophilic matrix. Areas of scattered calcification may be seen. Hyaline cartilage may undergo endochondral ossification.  CHONDROSARCOMA Malignant tumor characterized by cartilage formation, but not bone, by the tumor cells. 10% of all primary bone tumors of skeleton, but occur very rarely in the jaws.  HISTOLOGICAL FEATURES Composed of cartilage showing varying degrees of maturation and cellularity. Proliferation of atypical chondrocytes and cartilage that permeate medullary spaces Chondrocytic atypia takes the form of binucleation and multinucleation, nuclear pleomorphism and hyperchromatism, and more than one chondrocyte within a lacuna; Lobular growth pattern seen with centre of lobule showing greatest maturation and periphery showing immature cartilage along with a stroma of round / spindle cells.  EWING’S SARCOMA Primary malignant tumor of bone. Histogenesis is uncertain. Comprises 6 % – 10 % of all primary bone tumors. Earlier believed to arise from endothelial cells, hematopoietic cells or undifferentiated mesenchymal cells. Now proved to be having neuroectodermal origin. HISTOPATHOLOGICAL FEATURES: Composed of small round cells with indistinct cell outlines but well defined nuclear boundary. Tumor cells proliferate in sheets without any pattern. Large areas of necrosis and haemorrhage also seen. Diagnosis difficult, as it is similar to lymphomas, small cell osteosarcoma, embryonal rhabdomyosarcoma etc.