Bone Tumors PDF

# BONE TUMORS ## I. OSTEOMA - Benign tumor of bone - Most commonly arises on the surface of facial bones - Associated with Gardner syndrome ## II. OSTEOID OSTEOMA - Benign tumor of osteoblasts (that produce osteoid) surrounded by a rim of reactive bone - Occurs in young adults < 25 years of age (m...

# BONE TUMORS ## I. OSTEOMA - Benign tumor of bone - Most commonly arises on the surface of facial bones - Associated with Gardner syndrome ## II. OSTEOID OSTEOMA - Benign tumor of osteoblasts (that produce osteoid) surrounded by a rim of reactive bone - Occurs in young adults < 25 years of age (more common in males) - Arises in cortex of long bones (e.g., femur) - Presents as bone pain that resolves with aspirin - Imaging reveals a bony mass (< 2 cm) with a radiolucent core (osteoid). - Osteoblastoma is similar to osteoid osteoma but is larger (> 2 cm), arises in vertebrae, and presents as bone pain that does not respond to aspirin. ## III. OSTEOCHONDROMA - Tumor of bone with an overlying cartilage cap; most common benign tumor of bone - Arises from a lateral projection of the growth plate (metaphysis); bone is continuous with the marrow space. - Overlying cartilage can transform (rarely) to chondrosarcoma. ## IV. OSTEOSARCOMA - Malignant proliferation of osteoblasts - Peak incidence is seen in teenagers; less commonly seen in the elderly - Risk factors include familial retinoblastoma, Paget disease, and radiation exposure. - Arises in the metaphysis of long bones, usually the distal femur or proximal tibia (region of the knee) - Presents as a pathologic fracture or bone pain with swelling - Imaging reveals a destructive mass with a 'sunburst' appearance and lifting of the periosteum (Codman triangle). - Biopsy reveals pleomorphic cells that produce osteoid. ## V. GIANT CELL TUMOR - Tumor comprised of multinucleated giant cells and stromal cells - Occurs in young adults - Arises in the epiphysis oflong bones, usually the distal femur or proximal tibia (region of the knee) - 'Soap-bubble' appearance on x-ray - Locally aggressive tumor; may recur ## VI. EWING SARCOMA - Malignant proliferation of poorly-differentiated cells derived from neuroectoderm - Arises in the diaphysis oflong bones; usually in male children (< 15 years of age) - 'Onion-skin' appearance on x-ray - Biopsy reveals small, round blue cells that resemble lymphocytes. - Can be confused with lymphoma or chronic osteomyelitis - t(11;22) translocation is characteristic. - Often presents with metastasis; responsive to chemotherapy ## VII. CHONDROMA - Benign tumor of cartilage - Usually arises in the medulla of small bones of the hands and feet. ## VIII. CHONDROSARCOMA - Malignant cartilage-forming tumor - Arises in medulla of the pelvis or central skeleton ## IX. METASTATIC TUMORS - More common than primary tumors - Usually result in osteolytic (punched-out) lesions - Prostatic carcinoma classically produces osteoblastic lesions.