Pagets disease Tumors and tumorlike lesions of bone

Paget’s disease, Tumors, and tumor-like lesions of bone

Paget’s disease Is a form of osteodystrophy characterized by disorganized formation and remodeling of bone unrelated to functional requirements. The etiology still remains unclear, but it is thought to be due to a primary dysfunction of osteoclasts and there is evidence that the disease has a viral etiology.

The three progressive and overlapping phases: § An initial osteolytic phase. § An active stage § An osteoblastic or sclerotic phase.

Clinical Features § waddling gait § pathological fractures of bones § progressive enlargement of the skull and facial bones § bone pain, and sensory and motor disturbances related to cranial nerve

Oral manifestations With progressive enlargement of the maxilla, the alveolar ridge become thickened and widened, the palate flattened and there is increasing facial deformity. In addition to incompetence of the lips. In dentate patients, derangement of the occlusion, spacing of the teeth, and retroclination of incisors and palatoversion of posterior teeth may be striking.

In edentulous patients, difficulties in wearing dentures and the need to have these remade periodically as the jaws increase in size are common complaints. Other important oral manifestation are related to involvement of the teeth which often show hypercementosis and may become ankylosed, leading to difficulty in extraction. Root resorption may also occur in the osteolytic phase.

Radiographic features Variable but reflect the different stages of the disease. There are ill-defined and irregular radioopaque areas producing a characteristic cotton-wool appearance. In the skull, thickening of the outer table of the vault and loss of distinction between the tables and diploe. In the jaws, loss of the lamina dura, hypercementosis, and ankylosis.

Histopathology combinations of osteoclastic and osteoblastic activity unrelated to normal function. During the early osteoporotic phase, osteoclastic resorption are dominates. The resorbed areas are filled by cellular and vascular fibrous marrow within which new bone forms and this in turn is remodeled and replaced by further new bone.

As a result of the remodelling activity the bone trabeculae show numerous criss -crossing, resting, and scalloped reversal lines which stain deeply with hematoxylin.

These lines give the bone a characteristic mosaic appearance. As more and more bone is formed within the lesion, the disjointed trabeculae fuse to form dense sclerotic masses of mosaic bone. As the disease becomes less active so the marrow becomes less vascular, and osteoclastic and osteoblastic activity is decreased. The cementum consequently may show the characteristic mosaic appearance.

In the diagnosis of Paget's disease, the serum calcium and serum phosphorus levels are usually within normal limits but the serum alkaline phosphatase level is often raised. Patients with Paget's disease may develop high output cardiac failure. Sarcomatous change is a rare complication occurring in about 0. 1 - 0. 2 % of patients overall.

CENTRAL GIANT CELL GRANULOMA Usually presents clinically as a swelling of the bone, and growth may sometimes be rapid. When the cortical plate is perforated the lesion may present as a peripheral giantcell granuloma. Some cases are symptomless and are first detected on routine radiological examination.

Radiographically a well-defined radiolucent area with thinning and often expansion of the cortex. Some are characteristically multilocular. Involved teeth may be displaced and their roots may show resorption.

Histopathology Large numbers of multinucleate, osteoclast-like giant cells lying in a vascular stroma which is rich in small, spindleshaped cells having oval or fusiform nuclei. Foci of extravasated erythrocytes and granules of haemosiderin pigment are common in the stroma. Sparse strands of collagen fibers partly subdivide the lesion which may also contain a few trabeculae of osteoid or bone.

Is a condition of unknown etiology. It has been suggested that it could be a reaction to some form of haemodynamic disturbance in bone marrow perhaps associated with trauma and hemorrhage. It is impossible to distinguish histologically from a focal lesion of hyperparathyroidism, which must be excluded by biochemical investigations.

TUMOURS OF BONE

CLASSIFICATION OF TUMOURS OF BONE FORMING TUMOURS FIBROUS TUMOURS § A-Benign: osteoma § osteoblastoma § B- Malignant: Osteosarcoma § A-Benign: Cemento-ossifying fibroma § B-Malignant: fibrosarcoma of bone § CARTILAGE-FORMING TUMOURS § A-Benign: chondroma § osteochondroma § B-Malignant: Chondrosarcoma § GIANT-CELL TUMOUR § Marrow tumours : Myeloma § Other types § TUMOUR LIKE LESION IN BONE: § A-Langerhans cell histiocytosis § B-Haemangioma of bone § METASTATIC TUMOURS

Osteoma is a benign, slow-growing tumor consisting of well-differentiated mature bone. It may arise as a central or sub-periosteal lesion and is more frequent in the mandible than maxilla. The majority of tumors are diagnosed in adult life.

Radiographic features Clearly circumscribed radioopaque lesion

Histologically Osteomas can be divided into compact (or ivory) and cancellous types. The compact osteoma consists of a mass of dense lamellar bone with few marrow spaces, the cancellous type is made up of interconnecting trabeculae enclosing fatty or fibrous marrow.

Osteosarcoma Is the commonest primary malignant tumor of bone but is relatively rare in the jaws. Most patients with jaw tumors are around 30 years of age at diagnosis and this is about a decade later than for osterosarcoma elsewhere in the skeleton. Occasionally, the tumor presents in older patients

In the jaws, slightly more common in the mandible than maxilla. The tumor presents as a fairly rapidly enlarging swelling that may be accompanied by pain, numbness of the lip, trismus, and displacement and loosening of teeth. Nasal obstruction and symptoms referable to the eye may also be features of maxillary tumors. Ulceration of overlying skin or mucosa is a late feature.

Radiographic features Depend on the amount of normal bone destroyed by the tumour and the amount of neoplastic bone formed within the lesion. Predominantly osteolytic tumors produce irregular areas of radiolucency whereas sclerosing types, in which much tumor bone is formed, . produce irregular areas of radio opacity. The two patterns may coexist in different parts of the same tumor.

When the cortical plates are perforated, the periosteum is raised and the tumor mass extend into the surrounding soft tissues. This may be associated with a characteristic radiographic appearance in which trabeculae of bone radiate perpendicularly around the lesion producing the classical sun ray appearance. A symmetrically widened periodontal ligament space has been reported as a feature of very early lesions.

Microscopically show considerable variation in pattern, but by definition are malignant tumors characterized by the direct formation of bone or osteoid by the tumor cells. In addition to bone and osteoid (osteoblastic type) the malignant cells may produce abundant fibrous tissue (fibroblaslic type) and/or cartilage (chondroblastic type).

CHONDROSARCOMA

Histologically Chondroma is a benign tumor characterized by the formation of mature cartilage. However, the presence of a high degree of cellularity and of plump, often binucleate cells should alert suspicion that the tumor is a well differentiated chondrosarcoma. Less well-differentiated chondrosarcomas may show obvious cytological features of malignancy.

Calcification and endochondral ossification may occur in both benign and malignant tumors and this is reflected in their variable radiographic appearances. It is important to differentiate ossification in a chondrosarcoma from a chondroblastic osteosarcoma; direct bone formation by malignant cells is seen only in osteosarcoma

LANGERHANS CELL HISTIOCYTOSIS (LCH)

Unifocal(solitary)eosinophilic granuloma § affects patients under 20 years of age and is more common in males. The cranium, jaws, ribs, and long bones are the most common sites. Jaw lesions are most frequent in the mandible. § Radiographs show a focal osteolytic lesion that may be well or poorly demarcated.

Multifocal eosinophilic granuloma more common in the mandible and extensive destruction results in loss and/or loosening of teeth which on radiographs may appear to be floating in air. hepatospleenomegaly and lymphadenopathy may be present. When the orbit and posterior pituitary are also involved the patient presents with the classical triad of Hand-Schuller-Christian syndrome. Skull defects, exophthalmos, and diabetes insipidus. The prognosis is generally good.

Progressive (acute) disseminated histiocytosis (Letterer-Siwe disease) affects infants or young children, presents with fever, skin rashes, hepatospleenomegaly, lymphadenopathy, and pancytopenia.

Radiographically There are localized or diffuse osteolytic lesions in many bones, especially the skull, pelvis, and long bones. In the jaws, diffuse bone destruction may cause loosening and exfoliation of teeth and the teeth may appear to be floating in air. Death is related to intertcurrent infections and progressive anaemia and debility.

Histologically consist of poorly defined collections of histiocytes mixed with variable numbers of granulocytes (both eosinophils and neutrophils) and lymphocytes. Areas of haemorrhage, necrosis, and fibrosis may be seen and multinucleated giant cells are prominent in some lesions.