Thursday 2 - Witrak - Bone pathology Flashcards
Osteoporosis
Post menopausal (usually) bone resorption
Osteomalacia
osteois matrix insufficient from G.I mal-absorption
Osteomyelitis
Staph A. usually, subtle, nonspecific and hard to eradicate.
Paget's disease what is it Who does it effect and to what extent? symptoms? lab findings?
excessive breakdown and reformation of bone possibly from virus in osteoclasts. (widens bones, long bones)
up to 10-15 % in older patients usually ango-saxon
pain due to fractures
^ alkaline phosphatase, normal serum Ca, no hepatobiliary disease
Osteopenia
3 types
Generalized decrease in bone mineralization
can be:
Osteoporosis
Osteomalacia
Malignancy
Hyperparathyroidism can do what to bone?
increase the resorption of the bone, increasing serum Ca
Pathological fracture
fracture through deseased bone – usually refers to fracture through tumorous or tumor-like bone
What type of bone tissue cell produces alkaline phosphotase?
active osteoblasts, signals that there is active bone formation going on.
What event coincides with the fusing of the epiphyseal plate during puberty?
blood vessels entering into the epiphyseal plate
How do you get the active form of vit D
Vit D —-liver—-> Vid D (OH)1
Vit D (OH)1 —-PTH (kidney)—-> Vit D (OH)2
synth of active vit d inhibited by what
Phosphate and Vit D (OH)2 (that IS the active form)
Three things parathyroid hormone (PTH) does to bones and calcium
synthesizes the last step in activating Vit D (1 OH to 2 OHs)
stimulates osteoblasts to release osteoclast stimulating factor, which resorbs bone calcium.
stimulates uptake of calcium from the intestine to the blood.
Steps in forming new bone in a fracture?
Fibroblasts come in and morph into osteocartilagenous matrix, which goes on to form bone
Heterotopic ossification
ossification happening where it is not supposed to.
This is a joint that is formed from a break in bone
pseudoarthrosis
This fracture of the spine is usually painless and can cause kyphosis
wedge fracture
What doesn’t make sense about PTH with regards to osteoporosis?
there is a dimineshed PTH secretion, but still too much bone resorption.
Best prevention of osteoporosis
maximize peak bone mass in young adult hood
weight-bearing exercise and Ca supplementation
Hypercalcemia.
differential?
hyperparathyroidism or cancer until proven otherwise
What is in excess in rickets?
osteoid. not enough Ca co calcify the bone
Four examples of ways to get osteomalacia
Environmental
intestinal malabsorption (common in US)
liver or renal disease (impaired Vit D hydroxylation(second step in synth))
Rare congenital
Main lab finding for osteomalacia
^serum alkaline phosphatase
Patients with sickle cell tend to get what type of bacteria that causes osteomyelitis?
Salmonella
Where does most of pyogenic osteomyelitis begin?
metaphyseal marow space
Treatment for suppurative (purulent) osteomyelitis?
Early, aggressive IV antibiotics
surgical drainage
amputation in chronic cases
Pott’s disease
tuberculous osteomyelitis of the spine
Blastomycosis and coccidioidomycosis
Fungal forms of osteomyelitis
Avascular bone necrosis/infarction
causes?
What usually causes multiple infarcts?
best way to image?
Fractures, corticosteroids, alcoholism
corticosteroids
MRI
Unilateral hip hypercalcification. main thought in differential?
Paget’s
Osteogenesis imperfecta
clinical findings
congenital disorder of what
Smaller, bent bones
type 1 collagen
Classic example of purely osteolytic malignancy
Myeloma (cancer of plasma cells, effector B cells)
Classic example of purely osteoblastic malignancy
prostate cancer
Most common sources of metastatic tumor that involve the skeleton
Lung, Breast, Prostate
What is usually the first clinical finding of bone malignancy
Pathological fracture
Most common malignancy involving bone?
METASTATIC TUMORS i.e. cancer that came from a different type of tissue.
Most common type of bone tumors for kids?
for adults?
Kids: osteosarcoma
Adults: Chondrosarcoma
Osteochondroma. mostlikely benign or malignant?
benign
3 common malignant bone tumors
osteosarcoma
chondrosarcoma
ewing’s sarcoma
Common bone lesion in children (1 in 3) that looks like a mushroom
Where is it most common in the body?
metaphyseal fibrous defect (a non-ossifying fibroma)
Knees
Pain at night, Throbbing finger, bone deformity, young.
Asprin releaves pain
top of differential?
osteoid osteoma**
Soft, jello crud in epyphysis of bone.
Inbetween tumor, might be malignant might not be
Giant cell tumor.
Shepard’s crypt deformaty
congenital focal bone disorder of the trochantor of the femur
Characteristics of a bone x-ray that would make you think malignancy
not well circuscribed.
cortex is lytically destroyed
elevated pariostium (irregular osteoblastic change)
calcification in soft tissue.
only other thing in differential is severe osteomyelitis
Most feared primary bone cancer in young people.
Where does it usually occur?
osteogenic sarcoma.
sporatic, loves the knee
histology of osteosarcoma
some nuclii bigger than others, osteoblastic tumor cells making too much pink osteoid. (H&E stain)
Where can osteosarcoma metastasize in the example from class?
Lung
This type of tumor is often one of the largest
Chondrosarcoma.
Most aggressive and lethal primary bone tumors
often found where?
Histology?
who?
metastases?
Ewing’s sarcoma
Shafts of long bone
Wall to wall nucleii
young
often lung
Metaphyseal refers to what?
metaphysis of the bone, between the epiphysis and diaphysis
Myeloma
age group?
cancer of plasma cells (b cells)
older people
Osteiod osteoma gender ratio
M:F
3:1
