Bone Tumors

General Information An osteosarcoma is so called, because it is a cancerous tumor that is derived from a mesenchymal stem cell precursor (thus, by definition a sarcoma). The malignant cells produce immature woven bone, or osteoid, which is why the tumor is named...

General Information Benign neoplasm Composed of mature hyaline cartilage Arises from surface of bone from inner layer of periosteum Erodes the outer table of the cortex Does not grossly extend into medullary cavity Also known as juxtacortical chondroma More cellular...

General Information Intracortical osteosarcoma is an extremely rare type of osteosarcoma that arises within and is usually confined to the cortex of the bone. It is a high grade osteosarcoma that is confined to the cortex of a long bone Intracortical osteosarcoma is...

General Information High grade surface osteosarcoma is a type of high grade osteosarcoma that develops on the surface of the bone from the outer cortex. There is none to minimal medullary involvement The microscopic pathology is the same as a conventional osteosarcoma...

General Information Periosteal osteosarcoma is a distinct type of surface osteosarcoma (arises from the surface of the bone/periosteum) It arises from the inner layer of the periosteum and therefore elevates the periosteum and produces a periosteal reaction Periosteal...

General Information Parosteal osteosarcoma is a low grade, well differentiated fibroblastic tumor that produces bone/osteoid (immature woven bone). It arises from the surface of the bone, namely the outer layer of the periosteum. It is slow growing and slow to...

GENERAL INFORMATION Low Grade Intraosseous Osteosarcoma is a low grade malignant bone tumor that accounts for 1% to 2% of all Osteosarcomas. Constituent cells of the tumor form osteoid or immature woven bone.  CLINICAL DATA • More frequent in second and...

General Information Telangiectatic osteosarcoma is a variant of an intramedullary high grade osteosarcoma. Accounts for 3% of osteosarcomas Telangiectatic osteosarcoma is extremely lytic on X-rays. It demonstrates very little osteoid production. It is characterized by...

GENERAL INFORMATION Osteoma is a rare benign bone tumor, composed of mature osseous tissue.  It presents as a protruding mass of dense periosteal intramembranous bone, usually on surface of host bone. It is abnormally dense but is normal bone formed in the...

General Information Osteoid Osteoma is a benign osteoblastic (bone forming) tumor that is usually less than 2cm in size. It consists of a central vascularized nidus that represents the neoplastic tissue. The nidus is surrounded by normal reactive bone. It is usually a...

General Information Osteochondroma is an outgrowth of medullary and cortical bone A portion of the cartilaginous growth plate grows outward instead of longitudinally and forms the osteochondroma/exostosis (like a branch on a tree) It consists of bone covered with...

General Information Benign osteoblastic neoplasm with aggressive growth pattern (considered a benign aggressive tumor) Histologically it is similar to osteoid osteoma but is a larger size and grows progressively Consists of well vascularized connective tissue stroma...

GENERAL INFORMATION Nonossifying fibroma is a benign intracortical, multilocular and well circumscribed lesion that affects young patients. It originates from the proliferation of fibrous tissue and histocytes.  The most common location are the distal femoral and...

GENERAL INFORMATION Malignant Fibrous Histiocytoma (MFH) usually arises in soft tissue and is typically a malignant soft tissue sarcoma, but may arise from bone in 1% to 5% of all cases and accounts for 3% to 8% of all bone tumors. In this case it is called MFH of...

General Information Primary lymphoma of bone is defined as lymphoma arising within the medullary cavity of a bone in the absence of lymph node or organ involvement for at least 6 months after diagnosis Primary lymphoma of bone is rare (3% of primary bone tumors) and...

GENERAL INFORMATION Giant cell tumor (GCT) of bone is a benign but aggressive bone tumor originating from mesenchymal cells. Initially, described by Cooper and Travers in 1818 as an aggressive and destructive lesion of long bones, then Virchow first described the...

GENERAL INFORMATION Fibrous dysplasia is not considered a tumor; it is a developmental disorder of the bone. It appears similar to a tumor on radiological studies. Fibrous dysplasia is caused by the inability of the bone-forming tissue to produce mature bone due to a...

General Information Ewing sarcoma is a small round blue cell sarcoma It is a primary osseous neoplasm (cancer/sarcoma) composed of uniform, monotonous, small round blue cells without any matrix production Fourth most common primary malignancy of bone Approximately 5%...

General Information This is a benign proliferation of Langerhans cells usually accompanied with eosinophils, lymphocytes, neutrophils and scattered plasma cells. There may be solitary or multiple lesions confined to bone 70% of cases consist of a solitary lesion...

General Information Enchondromatosis is enchondral ossification or cartilage dysplasia.Occurs in two clinical disorders: Ollier’s Disease rare skeletal disorder Multifocal intramedullary proliferation of dysplastic cartilage Present in one bone or multiple bones with...

General Information Enchondroma is a benign indolent intramedullary hyaline cartilage neoplasm Accounts for 10% of all benign osseous tumors Limited growth, most lesions are less than 5 cm in maximal dimension Bones grow from a cartilaginous growth plate that...

GENERAL INFORMATION Desmoplastic fibroma is a benign but aggressive tumor composed of fibroblasts and myoblasts in heavily collagenized stroma. It's a very rare tumor with slow growth  and produces collagen. It characterized also by aggressive intramedullary...

GENERAL INFORMATION • Chordomas were first described by Virshow in 1957 and named as Chordoma by Ribbert in the 1890s. • Slow growing malignant primary bone tumor• Originates from residual of undifferentiated notochordal remnants in nucleus...

General Information Juxtacortical/Periosteal Similar to juxtacortical chondroma Periosteal lesion - cortical erosion Chondroid matrix calcification Similar to periosteal ogs (no hair on end periosteal reaction) Larger soft tissue mass/size (>3-4cm) Intramedullary...

General Information High grade malignant, cartilage-forming tumor Comprised primarily of noncartilaginous small, round, oval, or spindle shaped cells with islands of malignant cartilage dispersed throughout noncartilaginous component of tumor Osteoid may be present as...

General Information Dedifferentiated chondrosarcoma consists of a low grade malignant hyaline cartilage tumor associated with a high-grade nonchondroid spindle sarcoma. The two components are juxtaposed with abrupt clear demarcation line The high grade sarcoma is most...

General Information Malignant tumor Comprised of neoplastic chondrocytes With abundany, clear cytosplasm Little interveining matrix Foci of conventional chondrosarcoma may be present Clinical Presentation Signs/Symptoms: Pain and swelling There may be interference...

General Information Codman Tumor (old historical name for chondroblastoma) Cartilage Containing Giant Cell Tumor (Kolodney 1972) Calcifying Giant Cell Tumor (Ewing 1928) Clinical Data Rare; 1-2% all bone tumors Male predilection (2:1) Children and young adults; 90%...

GENERAL INFORMATION Bone island, also called an enostosis, is a benign bone tumor mostly encountered as an incidental and asymptomatic finding. They are round and small (2 to 20 mm) intramedullary condensations composed of lamellar cortical bone. Essentially it is...

GENERAL INFORMATION Benign Fibrous Histiocytoma is a rare tumor of mesenchymal origin. First described in 1958 by Dahlin. They are composed of two cell types, namely atypical fibroblasts and histiocytes, arranged in a storiform pattern. Lipid-filled cells may be...

General Information An aneurysmal bone cyst (ABC) is a benign bone tumor or neoplasm. It consists of a blood-filled multiloculated cavity with a thick fibrous lining. The lining is composed of mesenchymal spindle cells, capillaries, multinucleated giant cells, and...

General Information Primary intraosseous epithelial neoplasm Low-grade malignancy and predilection for tibia Associated with intraosseous fibro-osseous proliferation (osteofibrous dysplasia) Classic vs. Differentiated Classic – grow beyond cortex, older patients,...