develop.
COL1A1 or COL1A2 mutation --> decreased Production of Normal type 1 collagen, Bone, Ears, Eyes and Teeth effected. Confused with child abuse.
Osteogenesis Imperfecta
Rock-like bone due to a defect in metabolic pathways
Osteopetrosis
Cartilage degeneration and fragmentation, bone spurs, subchondral cysts; minimal inflammation
Osteoarthritis
Tumors may be a pathologic cause of
Fractures
Malignant, multiple risk factors, Codman's triangle, sunburst pattern
Osteosarcoma
Autosomal Dominant constitutive FGFR3 activation, failure of endochondral ossification
Achondroplasia – Dwarfism
Inflammatory pannus invading and destroying cartilage; severe chronic inflammation; joint fusion (ankylosis)
Rheumatoid Arthritis
Develop due to cystic or myxoid connective tissue degeneration; cyst wall lacks cell lining
May be multilocular, can enlarge through coalescence and degeneration of adjacent connective tissue
Ganglion cysts
Benign bone tumor, associated with Gardner’s Syndrome, facial bones
Osteoma
Slow-growing, low-grade tumors cause reactive cortical thickening; aggressive high-grade neoplasms destroy cortex and form soft tissue masses
Chondrosarcomas
Approximately 50% of familial disease and 10% of sporadic cases associated with mutations in the SQSTM1 gene: increase NF-κB activity, enhancing osteoclast activity
Paget Disease of Bone – Osteitis Deformans
Defective mineralization of cartilaginous growth plates (open physis) due to Vit D deficiency
Rickets
Malignant, multiple risk factors, Codman's triangle, sunburst pattern
Bulky, gritty, gray-white tumors, often have hemorrhage and cystic degeneration
Osteosarcoma
Aggressive, involves epiphysis, soap bubble appearance
Giant Cell Tumor
Nocturnal bone pain (secondary to excess prostaglandin E2 produced by proliferating osteoblast), that is relieved by Aspirin and NSAIDS
Osteoid Osteoma
Hereditary exostoses: associated with germline loss-of-function mutations in either EXT1 or EXT2 gene
Osteochondroma
Defective mineralization of osteoid (closed physis) due to Vit D deficiency
Osteomalacia
If nonunion persists, the malformed callus undergoes cystic degeneration and the luminal surface can become lined by synovial-like cells, creating false joint or pseudoarthrosis
Fracture Repair (gone wrong)
Benign tumor; all components of normal bone present, but do not differentiate into mature structures; arise during skeletal development
Fibrous Dysplasia
• By definition > 2cm in size
• Often arises in spine
Osteoblastoma
Heterozygous mutations in IDH1 and IDH2 genes; Benign, hands/feet
Chondroma
Association with HLA-B27 and absence of rheumatoid factor
Seronegative Spondyloarthropathies
Bone loss in disease --> brown tumor --> cystic degeneration is common
Primary hyperparathyroidism (secondary effect)
Most common benign bone tumor; attached to skeleton by bony stalk capped by cartilage
Osteochondroma (exotosis)
Neoplastic cells have acquired mutations in gene encoding histone 3.3
Giant Cell Tumor (Osteoclastoma)