soft tiss 2 Flashcards
(15 cards)
Aneurysmal bone cysts
usually related to trauma, show evidence of prior hemorrhage and contain multinucleated giant cells
Bone Tumors
Osteosarcoma > chondrosarcoma > Ewing sarcoma
Benign bone tumors
Occur in adolescents, > males
Cured by local excision
Round or oval masses
Characterized morphologically by a sclerotic band of reactive bone formation around a small central core of active bone formation
Trabeculae of woven bone surrounded by osteoblasts with loose, intervening CT
May expand, erode & cause compression fractures
Osteoid osteomas
arise from beneath the periostium or from the involve the cortex of long bones
Osteoblastomas
> 2 cm in diameter, painful
Osteoblastomas typically occur in vertebral bodies
Osteosarcoma – Malignant Bone Tumors
- Malignant neoplasm of osteoblasts generally occurs in childhood or adolescence in the metaphysis of long bones, > males
- Characterized by osteoid formation (non-mineralized new bone)
- Can arise from Paget’s disease of bone in elderly individuals
- Since tumor cells often digest & migrate through the bone cortex to lift the periosteum which is seen as a triangular shadow on X-rays referred to as Codman’s triangle
Giant Cell Tumor of Bone
Consist of multinucleated giant osteoclast-like cells
RANKL expressing mononuclear cells interdigitate among multinucleate giant tumors cells
Ewing sarcoma
Sheets of small round cells with little cytoplasm
6-10% bone tumors, second most common pediatric bone tumor 80%males
Tumor Metastasis to Bone
- Some tumors have a propensity to metastasize to bone (prostate cancer, clear-cell carcinoma of the kidney, and hepatocellular carcinoma)
- Breast and lung cancer metastases to (rib) bone can result in pathologic fractures
Diseases of Cartilage: Osteochondroma – benign tumors
- Osteochondromas are cartilage-producing, benign slow-growing tumors,
- > males, late teen-early adulthood
- Inactivation of both copies of the TS genes EXT1 or EXT2 are associated with hereditary or sporadic (autosomal dominant) disease
Chondrosarcoma: Malignant tumors
- Tumors of older individuals (>40 yrs, >males)
- Show extensive cartilage formation
- Appear as large, soft tissue masses with “popcorn” calcifications on x-ray
Osteoarthritis
- Osteoarthritis is a degenerative condition in older individuals (>50yrs)
- Age-related changes and repetitive minor joint trauma (most common joint disease)
- Osteoarthritis is thinning and erosion of articular cartilage
- In severe cases, subchondral cysts form in articular bone from leakage of synovial fluid between fractures
- Over time, microfractures develop in articular bone, resulting in more deformity and associated pain/Surgical joint replacement
Osteoarthritis (vs rheumatoid arthritis)
50-60 yrs age, not gender specific
Symptoms include joint pain, stiffness, crepitus (grating, cracking, popping sounds), limited mobility
Progressive degeneration without bone fusion
Rheumatoid Arthritis
20-40 yr, > women
Symptoms include joint pain, stiffness, limited mobility
Autoimmune disease, chronic inflammation causing synovitis
Results in bone fusion: ankylosis
Rheumatoid arthritis
- Untreated, RA damages articular cartilage, forms pannus (abnormal fibrovascular/granulation tissue over synovial cells on inside of joint) & causes ankylosis (joint fusion)
- Hand deformation results in “swan neck”
- Synovitis promotes synovial hyperplasia due to dense inflammatory infiltrate
- Diagnostic features: palisading histiocytes, rheumatoid factor and/or cyclic citrullinated peptide (CCP) autoantibody & altered synovial fluid
