BONE TUMORS

Bone tumors Bone tumors are classified into:  Primary bone tumors  Secondary bone tumors ( Metastasis) normal cell of origin Most are classified according to the normal cell of origin and apparent pattern of differentiation

Bone tumors Bone-forming tumors Cartilage-forming tumors Miscellaneous tumors Hematopoietic tumors Fibrous tumors

Primary Bone Tumors Bone-Forming tumors  Osteoma  Osteoid osteoma and osteoblastoma  Osteosarcoma Cartilage-Forming tumors  Chondroma (Enchondroma)  Osteochondroma  Chondrosarcoma Miscellaneous tumors − Ewing’s sarcoma  Giant cell tumor of bone

Bone-Forming Tumors Bone-Forming Tumors

Osteoma Osteoma Osteoma are benign lesions of bone that in many cases represent developmental aberrations or reactive growths rather than true neoplasms. Site; Site; Age; Age; Gross: Gross: Histology: Histology:

Osteosarcoma Osteosarcoma is a bone-producing malignant mesenchymal tumor. Osteosarcoma is a bone-producing malignant mesenchymal tumor.

Osteosarcoma Incidence: Incidence: Age: Age: Sex: Sex: Site : Site :

Osteosarcoma Distribution

Osteosarcoma Osteosarcoma Radiograph

Osteosarcoma Osteosarcoma Gross features

Bone-Forming tumors; Tumor Type LocationsAgeMorphology BENIGN OsteomaFacial bones, skull40-50Exophytic growths attached to bone surface; histologically resemble normal bon Osteoid osteomaMetaphysis of femur and tibia 10-20Cortical tumors, characterized by pain; histologically interlacing trabeculae of woven bone OsteoblastomaVertebral column10-20vertebral processes; histologically similar to osteoid osteoma MALIGNANT Primary osteosarcoma Metaphysis of distal femur, proximal tibia, and humerus Grow outward, lifting periosteum, and inward to the medullary cavity; microscopically malignant cells form osteoid. Secondary osteosarcoma Femur, humerus, pelvis >40Complications of polyostotic Paget disease; histologically similar to primary osteosarcoma

Cartilage - Forming Tumors

Osteochondroma Osteochondroma Morphology Osteochondromas are mushroom shaped and range in size from 1 to 20 cm. outer layerThe outer layer of the head of the osteochondroma is composed of benign hyaline cartilage varying in thickness inner portionNewly formed bone forms the inner portion of the head and stalk, with the stalk cortex merging with the cortex of the host bone.

Osteochondroma (exostosis) Gross

Osteochondroma (exostosis) Microscopic The cap is benign hyaline cartilage, resembling disorganized growth plate undergoing endochondral ossification. Newly formed bone forms the inner portion of the head and stalk

Chondrosarcoma Chondrosarcoma Chondrosarcomas comprise a variety of tumors sharing the ability to produce neoplastic cartilage Chondrosarcomas comprise a variety of tumors sharing the ability to produce neoplastic cartilage

Chondrosarcoma Chondrosarcoma Gross features SITE; SITE; pelvis, shoulder, ribs. rarely involve the distal extremities.

Chondrosarcoma Chondrosarcoma Microscopic These tumors are composed of lobules of cartilage with anaplastic chondrocytes in the lacunae and with focal enchondral ossification and calcification.

Cartilage-forming Tumors; Tumor TypeLocationsAgeMorphology BENIGNOsteochondromaMetaphysis of long tubular bones 10-30Bony excrescences with a cartilaginous cap; may be solitary or multiple and hereditary Chondroma Small bones of hands and feet 30-50Well-circumscribed single tumors resembling normal cartilage; arise with medullary cavity of bone; uncommonly multiple and hereditary MALIGNANT ChondrosarcomaBones of shoulder, pelvis, proximal femur, and ribs 40-60Arise within medullary cavity and erode cortex; microscopically well differentiated cartilage-like or anaplastic

Giant Cell Tumor This is a neoplasm that contains large numbers of osteoclast like giant cells admixed with mononuclear cells. These tumors are slightly more common in females.

Giant Cell Tumor Gross

Giant Cell Tumor Microscopic

METASTATIC BONE TUMORS Metastatic tumors are the most common malignant tumor of bone. Pathways of spread: Pathways of spread: Origin: Origin: The radiologic appearance of metastases The radiologic appearance of metastases