WT - Bone pathology Flashcards
Osteoporosis
- spongy/cortical bone loss despite nml mineralization and NML Ca, PO4, PTH, Alk phos
- via old age/dec estrogen –> inc bone resorp
- via drugs (steroids, alcohol, anticonvulsants, anticoagulants, thyroid replacement)
- via hypERparathyroidism, hypeRthyroid, mult myeloma, malabsorption, anorexia)
- vertebral compression fractures, Colles (distal radius)
dx: DEXA scan, T-score = -2.5 or fragility fracture
tx: bisphosphonates, teriparatide, SERMs (raloxifene), calcitonin, denosumab
osteopetrosis
- mut carbonic anhydrase –> lack of acidic envio –> defective osteoclasts –> failed bone resorption –> thickened, dense bones
- pancytopenia, extramedullary hematopoiesis, CN impingement, hydrocephalus
XR: symmetric sclerosis
tx: BM transplant (monocytes –> osteoclasts)
osteomalacia/rickets
- defective mineralization of osteoid (osteomalacia)
- defective cartilaginous growth plates (rickets, children)
labs: dec vit D –> dec serum Ca, normal PTH, inc ALP
XR: looser zones (pseudofractures), epiphyseal widening and metaphysical cupping, bow legs, rachitic rosary, craniotabes (soft skull)
tx: vit D and Ca
Osteitis deformans
(Paget’s)
- localized disorder of bone remodeling
- inc osteoclastic activ followsd by inc osteoblastic activity –> poorly formed bone
- mosaic pattern of woven and lamellar bone
- long bone chalk stick fractures
- AV shunts –> high output HF
- inc risk osteosarcoma
- inc hat size, hearing loss
- OLDER pt, 70s
Stages: lytic (C), mixed (C, B), sclerotic (B), quiescent
labs: NML serum Ca, phosphorus, PTH. INC ALP
avascular necrosis of bone
- infarction of bone and marrow, very painful
- usu at femoral head (watershed zone, insufficiency of medial circumflex femoral a.)
- via corticosteroids, alcoholism, sickle cell disease, trauma, SLE, the Bends, LEgg-Calve-Perthes disease (idiopathic), Gaucher disease, Slipped capital femoral epiphysis - CASTS Bend LEGS
osteitis fibrosis cystica
- primary hypERthyroidism
- brown tumors (giant collection of osteoclasts)
- subperiosteal thinning
- idiopathic or parathyroid hyperplasia, adenoma, CA
labs: dec serum Ca
secondary hypERparathyroidism
- often as compensation for CKD (dec PO4 excretion and dec prod of activ vit D)
labs: dec serum Ca
osteochondroma
location: metaphysis of long bones
- lateral bony projection of growth plate (continuous w/ marrow space)
- RARELY –> chondrosarcoma
- most comm BENIGN bone tumor
- males < 25
osteoma
location: surface of facial bones
- BENIGN
- associated with Gardner syndrome (FAP)
- middle aged
osteoid osteoma
location: cortex of long bones, diaphysis region.
- BENIGN tumor of osteoblasts surr by rim of reactive bone
- bone pain worse at NIGHT
- relief w/ NSAIDs
- bony mass (<2cm) with radiolucent osteoid core
osteoblastoma
location: vertebrae
- BENIGN, similar histo to osteoid osteoma but LARGER, and NON-responsive to NSAIDs
- M>F
chondroma
location: medulla of small bones of hands/feet
- BENIGN tumor of cartilage
- may erode but doesn’t invade cortex
giant cell tumor
location: epiphysis of long bones (knee region)
- locally aggressive benign tumor, neoplastic mononuclear cells that express RANKL and reactive multinucleate giant cells (OSTEOCLASTOMA)
- soap-bubble” on XR
- 20-40 y/o
osteosarcoma
location: metaphysis of long bones (often knee)
- pleomorphic osteoid-producing cells (malignant osteoblasts)
- AGRESSIVE, MALIG
- presents as painful enlarging mass/soft-tissue swelling
- 20% of all primary bone cancers
- peak incidence of primary tumor in males <20yr
- XR: codman triangle, sunburst
- primary: responsible to surg/chemo
- secondary: poor prog (sec via Paget, bone infarcts, radiation, familial retinoblastoma, Li-fraumeni syndrome)
chondrosarcoma
location: medulla of pelvis, proximal femur and humerus (CENTRAL)
- MALIGNANT chondrocytes, small calcific
- NO osteiod/bone prod
