BONE TUMORSBONE TUMORS

Bone tumorsBone tumors

Bone tumors are classified into: Primary bone tumors Secondary bone tumors ( Metastasis)

Most are classified according to the normal normal cell of origincell of origin and apparent pattern of differentiation

Bone tumorsBone tumors

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

Primary Bone TumorsPrimary Bone Tumors

Bone-Forming tumorsBone-Forming tumors Osteoma Osteoid osteoma and

osteoblastoma Osteosarcoma

Cartilage-Forming tumorsCartilage-Forming tumors Chondroma

(Enchondroma) Osteochondroma Chondrosarcoma

Miscellaneous tumorsMiscellaneous tumors− Ewing’s sarcoma Giant cell tumor of

bone

Bone-Forming TumorsBone-Forming Tumors

OsteomaOsteoma

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

OsteosarcomaOsteosarcoma

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

Osteosarcoma Distribution

Osteosarcoma Osteosarcoma

Radiograph

Osteosarcoma Osteosarcoma Gross features

Bone-Forming tumors;Tumor TypeTumor Type LocationsLocations AgeAge MorphologyMorphology

BENIGNBENIGN Osteoma Facial bones, skull 40-50 Exophytic growths

attached to bone surface; histologically resemble normal bon

Osteoid osteoma Metaphysis of femur and tibia

10-20 Cortical tumors, characterized by

pain; histologically interlacing trabeculae

of woven bone

Osteoblastoma Vertebral column 10-20 vertebral processes; histologically similar to osteoid osteoma

MALIGNANTMALIGNANT Primary

osteosarcoma Metaphysis of distal femur, proximal tibia,

and humerus

10-20 Grow outward, lifting periosteum, and

inward to the medullary cavity; microscopically

malignant cells form osteoid.

Secondary

osteosarcoma Femur, humerus,

pelvis >40 Complications of

polyostotic Paget disease;

histologically similar to primary

osteosarcoma

Cartilage -Forming Cartilage -Forming TumorsTumors

Osteochondroma Osteochondroma Morphology

•Osteochondromas are mushroom shaped and range in size from 1 to 20 cm. •The outer layerouter layer of the head of the osteochondroma is composed of benign hyaline cartilage varying in thickness•Newly formed bone forms the inner portioninner 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

ChondrosarcomaChondrosarcoma

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

ChondrosarcomaChondrosarcomaGross features

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

ChondrosarcomaChondrosarcomaMicroscopic

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 Type Locations Age Morphology

BENIGN Osteochondroma Metaphysis of long tubular bones

10-30 Bony excrescences with a cartilaginous cap; may be solitary

or multiple and hereditary

Chondroma Small bones of hands and feet

30-50 Well-circumscribed single tumors resembling normal

cartilage; arise with medullary cavity of bone; uncommonly multiple and

hereditary

MALIGNANTChondrosarcoma Bones of shoulder,

pelvis, proximal femur, and ribs

40-60 Arise 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 TumorGross

Giant Cell TumorMicroscopic

METASTATIC BONE METASTATIC BONE TUMORSTUMORS

Metastatic tumors are the most common malignant tumor of bone.

Pathways of spread:Pathways of spread:

Origin:Origin: The radiologic appearance of metastasesThe radiologic appearance of metastases