Pathoma - MSK - Bone Tumors Flashcards
Is an osteoma benign or malignant and what is the most common location?
Benign tumor of bone
Most commonly arises on teh surface of facial bones
What bone tumor is commonly associated with Gardner syndrome
Osteoma
Gardner = familal adenomatous polyposis + fibromatosis in the retroperitoneum + osteoma of the facial bone
What is osteoid osteoma a tumor of?
Benign tumor of osteoblasts (that produce osteoid) surrounded by a rim of reactive bone
Where is the common location of an osteoid osteoma?
Cortex of long bones - usually within the diaphysis
What is the age group usually affected by osteoid osteomas?
Young adults < 25 y/o (more common in males)
Describe imaging and presentation of osteoid osteoma
Presents as bone pain that resolves with aspirin
Imaging reveals a bony mass (< 2 cm) with a radiolucent core (osteoid)
Differentiate between an osteoid osteoma and an osteoblastoma
Osteoid osteoma:
- Smaller (< 2 cm); within cortex of diaphysis; bone pain responds to aspirin
Osteoblastoma:
- Larger (> 2 cm); within the vertebrae; bone pain does not respond to aspirin
What is an osteochondroma
Tumor of bone with an overlying cartilage cap
Where does an osteochondroma arise from
Arises from a lateral projection of the growth plate (metaphysis); bone is continuous with bmarrow space
What is a complication of osteochondroma
Overlying cartilage can transform (rarely) into chondrosarcoma
What is an osteosarcoma?
Malignant proliferation of osteoblasts
What is the age group usually affected by osteosaroma?
Peak incidence in in teenages; smaller and less common peak seen in the elderly
Bimodal distribution
What are predisposing factors for osteosarcoma
Familial retinoblastoma, Paget disease, radiation, Li-Fraumeni syndroms (p53 mutation)
What part of the bone does osteosarcoma commonly occur in?
Metaphysis of long bones (growth plate)
Usually the distal femur or proximal tibia (regin of the knee)
Describe imaging of osteosarcoma
A destructive mass with a sunburst appearance and lifting of the periosteum (Codman triangle)
What is the composition of a giant cell tumor
Tumor comprised of multinucleated giant cells and stromal cells
Locally aggressive benign tumor
What location do giant cell tumors commonly occur
Arise in the epiphysis of long bones (only tumor that arises in the epiphysis)
Usually in the distal femur or proximal tibia (region of the knee)
Describe the X-ray appearance of giant cell tumor
“Soap bubble” appearance due to reactive bone forming arund the tumor in the epiphysis
What is Ewing Sarcoma
Malignant proliferation of poorly differentiated cells derived from neuroectoderm
Describe location and population affected by Ewing sarcoma
Arises in the diaphysis of long bones
Usually in male children (< 15 y/o)
Describe biopsy of Ewing sarcoma
small, round blue cells that resembly lymphocytes
Describe X-ray of Ewing sarcoma
“Onion-skin” appearance - tumow will growth within meduallary center of bone and push outwards, causing the periosteum (outer layer) to lay down new layers of bone
What is the tranlocation characterstic of Ewing Sarcoma
t(11;22)
Differentiate chondroma from chondrosarcoma
Chondroma:
- Benign tumor of cartilage; arises in small bones of hands and feet
Chondrosarcoma:
- Malignant tumor of cartilage; arises in medulla of pelvis or central skeleton
