Boards Study Flashcards
Endothelin 1 has a role in:
osteoblastic tumor mets
genetic mutation in McCune Albright
G alpha subunit
Occult lytic bone mets with no known primary are typically:
lung
do radiation and chemo work for chondrosarcomas?
no
- EXCEPT for Dedifferentiated Chondrosarcoma
most likely site of mets?
spine
most like site of pathologic fracture
proximal femur
when you nail a pathologic fracture of the hip, which zones get radiation
the entire femur, because you spread the metastatic disease through the entire canal
depth-related resection guidelines for acral lentiginous melanoma
> 4mm depth is full ray amputation
<0.76mm is disarticulation
treatment of enchondromas of the digits?
can be treated with curettage and bone grafting
E-cadherin and Integrins in tumor cells:
E-cadherin decreases and allow migration from tumor of origin
Integrins increase and establish foci of metastasis
Maffucci syndrome
multiple enchondromas and hemangiomas
surgery for lymphomas typically involves:
intramedullary stabilization. that’s basically all.
chondroblastoma metastatic potential
can met to lungs in 2%
Survival rates of localized osteosarcoma
65-70%
most common axial site of a giant cell tumor
sacrum
most common sites of metastatic osteosarcoma
- lung (get CT chest)
- bone
Treatment of osteosarcoma
chemotherapy and wide resection
Treatment of chondrosarcoma
wide resection alone
All soft tissue sarcomas show this on MRI:
low T1 signal
high T2 signal
CD99+ immunohistochemistry means:
tumor is Ewing’s sarcoma
Enneking / MSK Tumor Society Classification
I = low grade II = high grade III = metastatic
A = intra-compartmental B = extra-compartmental
Low grade sarcomas: (all stage I tumors)
- parosteal osteosarcoma
- well differentiated intramedullary osteosarcoma
- intramedullary chondrosarcoma
- chordoma
- adamantinoma
- secondary chondrosarcomas (MHE, Ollier’s)
Treat with wide resection alone
High grade sarcomas (all stage II tumors)
- conventional osteosarcoma
- Ewing’s
- Dedifferentiated chondrosarcoma
- Malignant fibrous histiocytoma
- Secondary sarcomas (Paget’s, Irradiation, Bone infarc)
Treat with chemo and wide resection
Lesions in the tibia
adamantinoma
osteofibrous dysplasia
fibrous dysplasia
osteomyelitis
S100, CD1A immunostains
Langerhans cell histiocytosis (eosinophilic gran)
Keratin immunostain
Metastatic cancer
Adamantinoma
CD20 (b cell) immunostain
lymphoma
CD99 immunostain
Ewing’s
Keratin, S100 immunostain
Chordoma
CD138 immunostain
Myeloma
Only tumors you aspirate and inject cortisone
EOG
UBC
Tumors you curettage
- giant cell tumor
- ABC
- NOF
- chondroblastoma
Tumors that get Chemo
- high grade osteosarcoma
- Ewing’s tumor
- Mets
any high grade tumor
Mechanisms of Radiation therapy
production of free radicals
direct genetic damage
Tumors treated with Bisphosphonates
- Metastatic bone disease
- Myeloma
- Paget’s disease
- Polyostotic fibrous dysplasia
When do you give a bisphosphonate holiday?
after 5-8 years
If mets distal to elbow or distal to knee we should think:
lung carcinoma
Everything malignant in bone is (MRI findings):
Low T1 signal
HIgh T2 signal
IF Hgb low and ESR high, think:
myeloma
Criteria for internal fixation of an osseous lesion
>50% cortical destruction high stress site purely lytic pattern weight bearing pain pain following irradiation
after you prophylactically fix a metastatic lesion, you must:
GIVE RADIATION
- every single patient
also give denosumab or bisphosphonate
Bence jones proteins
light chains (kappa or lambda) release into the urine in multiple myeloma
systemic complications of myeloma:
- hypercalcemia
- nephropathy
- anemia
If Hgb <12 and ESR >50, think:
multiple myeloma
Characteristic xray findings of lymphoma:
long lesions
- can involve over 50% of bone length in the appendicular skeleton
when there is hyaline cartilage in the medullary cavity, ti is either:
enchondroma (not growing)
chondrosarcoma (growing)
Common secondary sarcomas:
- paget’s
- post irradiation
- sarcoma in a bone infarct
Geographic pattern of Paget’s disease:
caucasians of Anglo-saxon descent
- europe
- north america
- australia
- new zealand
bone disease caused by Paramyxovirus infection:
Paget’s disease
- long subclinical course
- disease localized to single organ system
- intranuclear virus capsid-like structures
Nuclear inclusion within the osteoclasts
Viruses implicated in Paget’s
- RSV
- Paramyxovirus
- Canine virus (?)
Lab findings in Paget’s
- elevated serum alk phos
- elevated urine collagen breakdown products
- – N-telopeptide
- – Hydroxyproline
most common types of post-radiation sarcomas:
- MFH
- osteosarcomas
Enchondroma on MRI
Low T1
High T2
Bone islands on MRI
Low T1
Low T2
Osteopoikilosis
multiple areas of bone islands
Most frequently presenting stage of osteosarcoma:
Enneking II B
poor prognostic factors for treatment of osteosarcoma:
- mets at presentation
- skip lesions in single bone
- post-treatment necrosis of <90%
IF you see a young person with malignant appearing tumor with chondroid appearance on histo, think:
osteosarcoma
- periosteal
- parosteal
standard subtype
Ewing’s Treatment:
chemo sandwich
poor prognostic factor for Ewing’s?
post chemo necrosis of <95%
Where will you see UBC?
proximal humerus
proximal femur
nowhere else
Treatment of UBC in proximal humerus
injection of methylprednisolone
Treatment of UBC in proximal femur
curettage, bone graft, internal fixation
Histology of Osteoblastoma:
loose fibrovascular connective tissue with OSTEOBLASTIC RIMMING
Most common benign tumor to go to the lungs
Giant cell tumor (2%)
Recurrence rates of curettage of a UBC:
High - around 70% in some series
What is responsible for low T1 and T2 signal in PVNS?
Hemosiderin
When you see periarticular erosions on both sides of a jont, you should think:
primary synovial process
- PVNS
- RA
- infection
Rheumatoid nodules show up on:
extensor surfaces
Gout crystals:
negatively birefringent
needle shaped
Lymph nodes soft tissue mets:
CARES
- clear cell
- angiosarc
- rhabdomyosarc
- epithelioid sarc
- synovial sarc
Epithelioid sarcoma stains with:
Keratin!!!! Strongly Keratin +
Denosumab
- RANK-L monocloncal Ab
- give for myeloma or metastatic disease or osteoporosis
Osteoblast markers
Vitamin D Osteocalcin RANKL Alkaline phosphatase TGF-b BMPs
Osteoclast Markers
RANK receptor Acid phosophatase Cathepsin K Calcitonin A/B integrin receptor
Istotropic nature of woven bone
mechanical characteristics are independent of direction of loading
In children, woven bone allows for:
resistance to fracture
What kind of bone is seen in fibrous dysplasia
GNAS mutation
- inability to form mature bone
- ALL Woven Bone
By age 2, most bone is:
Lamellar bone
Anisotropic nature of lamellar bone
mechanical properties of bone are dependent upon directionality of loading
Gene mutation for Melorrheostosis
LEMD3
Role of TGFb and BMPS in bone formation
osteoclasts eliminate bone and releases TGFb and BMP
- TGFb recruits mesenchymal stem cells
- BMPs turn these into osteoblasts
What are the coupling factors for bone resroption and bone creation:
TGF-b and BMP
Fibro-osseous Dysplasia
ACVR1
shoulder contractures
shortened first rays
Mineralization of the soft tissues
DO NOT OPERATE - they turn to stone
Overactivity of TGFb is:
Camarati Engelman Disease
- thicknening of the diaphyses (diaphyseal dysplasia)
RUNX2
Master regulator of the osteoblast
- mutation here = Cleidocranial Dysplasi
SOX9
transcription factor for cartilage
PPAR gamma
transcription factor for fat
Transcription factors for bone:
RUNX2
Osterix
Sclerostin
secreted by osteocytes
inhibits bone formation
high mechanical stresses will do waht to sclerostin levels?
will DROP sclerostin levels
- will increase if you cast someone, or otherwise unload the bones
TRAP does what:
helps acidify the matrix to resorb it
These chemical signals tell a bone to resorb:
- PTH
- Vitamin D
- Prostaglandin E
Bone chemical composition:
Ca10 P4 (6) - OH2
What is the only collagen which mineralizes?
Type I
What osteoblast secretion factor controls insulin secretionin the pancreas?
Osteocalcin
Recommmndation of daily calcium/D supplements
- 1200 mg caclcium
- 800mg D
Female athlete triad:
Decreased available energy
Disturbed Menses
Decreased bone mineral density
Treatment is: make the girls eat
3 Gene defects for osteoporisis
- Vitamin D receptor
- LDRP5
- COL1 gene
Inflammatory phase of fx healing: Growth Factors
- PDGF
- TGFB
- IL1, 6
- PGE2
Soft Callus Phase of Fx healing: Growth Factors
SOX9 –> COL2
Indian Hedgehog
Hard Callus Phase of Fx Healing: Growth Factors
Type X Collagen
RUNX2 –> Osteocalcin (osteoblasts)
Osteopontin
Characteristics of secondary chondrosarcoma following an osteochondroma:
low grade
curable with resection alone
<1% of the time
Workup of a bone sarcoma should include:
chest CT
- rarely need Abdomen or Pelvis due to extremely rare mets to viscera
A marginal resection is defined as
Through the margin and reactive zone of the tumor. Or through the pseudo capsule. Microscopic disease may be found here.