Lecture 104 - Bone and Soft Tissue Path Flashcards
what are the two kinds of bone formation
Endochondral ossification – cartilage model of bone is first made by chondrocytes, then osteoclats and osteoblasts replce with woven bone –> Lamellar bone Membranous ossification – woven Bone formed directly without cartilage; later remodelled to lamellar bone
Osteoclasts _____ bone Osteoblasts -____ bone
Ostoblasts – build bone by secreting collagen and catalyzing mineralization Osteoclasts – dissolve bone
what is the difference between woven bone and lamellar bone
osteoid is primarly composed of ______; mutations to this lead to ______
Woven – newly synthesized, proteinaceous, with no strucutral integrity if found in adults;
Lamellmar Bone – mineralized bone, differentiated and much stronge
Osteoid: Type 1 collagen; defective states = Osteogenesis imperfecta
Avascular necrosis –
- causes
- classical location
- complications
Etiology:
Alcohol, Sickle Cell disease, Endogenous Steroids, Pancreatitis, trauma, Idiopathic, Caisson (ASEPTIC)
classical location: Femoral head
Complication: Fracture and osteoarthrits
what is the most common cause of osteomyelitis
patients with sickle cell anemia are more predisposed to -________
FIRST AID:
– sexuall active young adult
– Sick cell
–IVDU
–cat/dog bites/scratches
–ivovlemtn of the vertebrae
80 - 90%: Staph Aureus
sickle: SA overall still most common; but predisposed to salmonella
– sexuall active young adult: Gonorrhea
– Sickle cell: Salmonella
–IVDU: Pseudomonas
–cat/dog bites/scratches: Pasteurella Mutocida
– pott disease: TB, caseus necrosis
what may be seen on XR of osteomyelitis
labs to order?
BOne Gross pathology – what two forms may be seen; what is the difference
labs: CBC – look for WBC
XR: lytic bone lesions
Sequestrum – necrosis of the bone which becomes shielded off
Involucrum – attempts to heal the bone
complications of osteomyelitis
Persistent Disease – 5 to 25% with chronic osteomyelitis
Fracture,
Amyloidosis – chronic infection/inflammation
Endocarditis / Sepsis - -
Squamous Cells carcinoma – in a sinus tract
Sarcoma – can occur at the site of the osteomyelitis (rare)
classic finding of skeletal syphilis;
how is syphilis which causes this typically acquired
Congential syphilis
Saber Shin (deformity of the shin,incresaed AP dimateter)
name 5 benign tumors of bone
Giant cell tumor
osteoma
osteoid osteoma
osteoblastoma
osteochondroma
Osteoma - typical locaiton
surface of facial bones and skull
a/w Garnder Syndrome
Osteoid Osteoma –
tumor of_____
typical size
who gets these
where do they occur
how do they present
how do they respond to ASA
Tumor of Osteoblats
<2cm
<25 yo males
Cortex of the long bone diaphysis
Present with bony pain
Pain allevaited by ASA
Osteoblastoma –
similaritiy with osteoid osteoma
3 key differences comapred to osteoid osteoma
similar - benign tumor of osteoblasts; same histology
Diffences:
> 2cm
Arises in vertebrae
Less painful, but the bony pain is not resolved with SAS
what are two malignant tumors of bone
Ewing Sarcoma
osteosarcoma
what is the only bone tumor of the Epiphysis ?
who gets these?
where do they occur?
what is the classical appearnace on XR?
giant cell tumor
Young audlts ages 20-40 yo
Distal femur, Proximal tibia
XR: Soap bubles
osteosarcoma –
who gets these tumors?
what are some risk factors?
what part of the bone does it occur?
Classic XR findng?
Bimodal peak incidence – teenagers and Elderly
RF: mutations to RB, P53, rdaiaotin, Paget’s disease
Where: metaphysis tumor of long bones
XR findign: codmans angle
what the malignant tumor of the diaphysis of long bone
what cells sare these derived form?
what is the assoicated genetic change in these cancerous cells?
what is the classical XR finding
what is seen on histo
Ewing Sarcoma
derived from Neuro-ectoderm
11:22 translocation
XR: Onion skinning (periosteum activation)
Histo: small round blue cells, homor Write rosettes
On Xray you find a bony outgrowth, which on histology has a cartilage cap…what is the dx?
who gets these tumors
where in the bone ?
if there are multple of them, it may be part of what disorder?
Dx: osteochondroma –
Males < 25 yo
where: metaphysis – grows outward leading to bony growth but then with cartilage cap
Usually solitary but if multiple may be part of Multiple Hereditary Exostosis (AD disorder)
name 3 tumors of cartilage
which are benign vs malignant
where in the bone do cartilage tumors arise?
enchondroma – benign
chondroblastoma – benign
chondrosarcoma – malignant
all arise inth medulla of the bone
patient presents with bony widening of the metapyhsis of one of his fingers; otherwise asyptomatic. what is the dx?
what are two associated syndromes
enchondroma –
classically arises in the digt
a/w Ollier disease –if there are multple
a/w maffucci Syndrome – if there is hemangioma
patient foind to have benign cartilage tumor of the epiphysis; on histology there is “chicken wiring” – what is the dx?
Chondroblastoma
ChondroSarcoma –
benign vs malignant?
where do these tumors occur?
Central skeleton (pelvis, shoulder, ribs)
malignant
what is more common, primary bone tumors or metastatic bone tumors?
what are the most common mets to the bone?
how does this appear on imaging?
except for…
mets
mets to the bone: prostate, breast, kindey, lung
appears as lytic lesion on imaing, except for prostate which is osteoblastic on imaging
Fibrous dysplasia -
what is it
what is seen on histo
what may be seen clinically (a/w what othe syndrome)
Benign, localized area of developmental arrest
Histo: Persistent Woven Bone; “Chinese Characters”
A/w McCune Albright Syndrome — cafe au lait skin spots; coast of maine
