Bone tumors. Cartilage forming tumors Chondroma Benign tumors of hyaline cartilage probably develop from slowly proliferating rests of growth plate cartilage.

Bone tumors

Cartilage forming tumors• Chondroma

• Benign tumors of hyaline cartilage probably develop from slowly proliferating rests of growth plate cartilage

• Age: 30-50• Site: located in the metaphyseal region of tubular

bones ( short tubular bones of the hands and feet)• Usually solitary• But may multiple in:• Ollier disease : multiple chondromas involving one

side of the body• Maffucci syndrome: Multiple chondrmas with soft benign

vascular tumors( angiomas) of soft tissue.

• Enchondromas : arise within the medulla • Juxtacortical chondromas: arise on the bone

surface

Osteochondroma• Osteochondromas are also called exostoses• It is the most common benign tumor of bone

• Age: 10-30

• Site: metaphysis of long tubular bones, especially about the knee

• Male-to-female ratio of 3 : 1

• Benign cartilage-capped outgrowths attached by a bony stalk to the underlying skeleton.

Development over time of an osteochondromabeginning with an outgrowth from the epiphyseal cartilage

• Solitary osteochondromas are usually first diagnosed in late adolescence and early adulthood

• Usually follow a benign course.

• Multiple osteochondromas become apparent during childhood, occurring as multiple hereditary exostosis, an autosomal dominant disorder.

• Rare sarcomatous change.

Chondrosarcoma• Malignant bone forming tumor.• Age: most patients are age 40 or older • Site: Arise in the pelvis, shoulder, and ribs • Men to female ratio: 2-1. • Classified according to site and histologic

variants - intramedullary - juxtacortical• Metastasize hematogenously to the lungs and

skeleton

Miscellaneous Tumors

• A. Giant cell tumors (osteoclastoma )• Locally malignant tumor of bone

• Age: occurs between 20 – 40 years of age.

• Site: arises in the ends of long bones particularly in relation to knee joint, jaw, radius and clavicle.

• X ray : large, lytic, and eccentric (soap bubble appearance)

• Causes eccentric expansion of the affected bone and becomes covered by a thin shell of bone that yields under pressure giving (egg shell crackling).

• Infiltrates the surrounding tissues. The cut section shows areas of hemorrhage, necrosis and cyst formations

• 4% metastasize to the lungs• Complications: 1- Pathological fracture 2-It may change into frankly malignant

tumor

• B. Ewing sarcoma

• Anaplastic malignant bone tumor

• Age: 10-20

• Site: Diaphysis of femur, tibia, ribs and pelvis are the favored sites.

• Male predominance

• Characterized by an 11;22 translocation

• It follows an extremely aggressive course with early metastases

Miscellaneous Tumors

Tumor-like lesions• Fibrous bone defect

• 30-50% of all children older than age 2• Developmental defects rather than true

neoplasms. • Majority are smaller than 0.5 cm and arise in the

metaphysis of the distal femur or proximal tibia • 50% are bilateral or multiple• Larger lesions (5-6 cm) develop into

nonossifying fibromas.

Fibrous dysplasia• Unknown origin and develops at any age in the long

bones. • Pathology: Fibrous proliferation intermixed with poorly

formed, haphazardly arranged trabeculae of woven bone (not line by osteoblasts) progressively replace normal bone.

• Types: a- Monostotic: Affecting one bone. b- Polystotic: Affecting more than one. • The affected part is expanded by grey white fibrous

tissue which replaces the medulla and produce thinning of the cortex.

• Complications: Deformity and pathological fractures. Rarely it transforms into fibrosarcoma.

75% of bone metastasis originate from

Cancers of prostate breast kidney lung

thyroidMetastatic lesions are multifocal

Produce a lytic and or blastic reaction

Bone metastasis

Bone metastasis