12 Ortho/soft tissue Pathology Flashcards
what gene is mutated in achondroplasia? is it recessive or dominant?
1) FGFR3 gene.
2) Autosomal dominant
what does the FGFR gene mutation do to cause the bone to do?
it inhibits cartilage proliferation at the growth plates therefore preventing elongation
Which disease is caused by mutations in the gene coding for collagen type 1?
osteogenesis imperfecta.
what are some of the characteristics for osteogenesis imperfecta? (3)
blue sclera
brittle bones
bad teeth
what are the two different forms of osteomylitis?
pyogenic
granulomatous
(these are divided by their histology)
what generally causes pyogenic osteomyelitis in 1) adults, 2) neonates, and 3) sickle cell patients?
1) staph aureus in adults
2) Group B strep and HIB in neonates
3) Salmonella in sickle cell
what are the two most common types of osteoporosis?
Post menopausal
Senile
what causes rickets?
A defect in bone mineralization due to vitamin D deficiency
what is the difference between rickets and osteomalacia?
rickets in children (distorted bones) osteomalacia in adults (weaker bones but not generally deformed)
T/F Hyperparathyroidism and chronic renal disease can result in osteoporosis?
True, secondary osteoporosis.
why does chronic renal disease result in osteoporosis?
The kidney is messed up and doesn’t secrete as much Phosphate. This results in increased levels of PTH in the blood b/c it wants to get rid of phosphate. (increased PTH) beyond normal results in more CA+ in the blood by breaking down bone.
where do bone calluses form?
often from a bone fracture
what causes pagets disease? what is the most severe outcome of pagets disease?
Paramyxovirus infection. Pagets disease can transform into osteosarcoma in a few patients resulting in death.
what are the 3 phases of pagets disease? what is the overall result the bone that is formed?
1) initial osteolytic, followed by mixed lytic/blastic, lastly osteosclerotic
2) It ends up forming a mosiac pattern of weakened lamellar bone.
T/F Fibrous dysplasia shows woven bone with osteoblastic rimming?
False, there is no osteoblastic rimming here.
which diseases cause osteoblastic rimming?
1) osteoblastoma
2) osteoid osteoma
what disease is this describing: benign tumor like lesion of the bone characterized by localized developmental arrest?
Fibrous dysplasia
what are the 3 forms of fibrous dysplasia?
1) monostatic 70% (affects single bone)
2) Polystatic 27%
3) McCune albright syndrome (most important one)
what 4 things describe McCune albright syndrome?
1) polystotic (many bones only on one side of body)
2) Cafe au-lait spots
3) endocrinopathies (ex: precocious puberty)
4) GNAS 1 mutation
which disease shows a Chinese character like pattern in the woven bone?
fibrous dysplasia
what causes osteoarthritis?
wear and tear from old age that stems from breakdown of cartilage over time with assocatiated cytokine production resulting in secondary changes in the bones.
what are some secondary changes in the bones associated with osteoarthritis?
1) burnishing
2) subchondral cysts
3) osteophytes
which joint is specifically not involved in RA?
Distal interphalangeal joint (DIP)
which joints are usually involved in RA?
MCP and PIP joints. Characteristic: bilateral and involve multiple joints.
which disease forms a pannus?
RA
which disease forms necrotizing granulomas in the joints?
RA
What is rheumatoid factor?
An IgM directed against the Fc portion of IgG
what causes gout?
too much monosodium urate.
what are some characteristics of gout crystals?
1) neg. birefringent (yellow=parallel)
2) large spicules
