Tumor: Bone Lesions

Question 1

Mechanism for NSAIDs against OO

Answer 1

PG E2 inhibitor

Question 2

AEIOU/Y diaphyseal lesions

Answer 2

Adamantanoma
Eosinophilic granuloma
Infection
OO/osteoblastoma
Uings aka Ewings
Y - fibrous dysplasia / lymphoma / myeloma

Question 3

Dx OO

Answer 3

CT
Nidius <2cm - this is the immature bone

Question 4

Treat OO

Answer 4

Monitor - do self resolve, just can’t predict when
NSAIDs
RFA
En block resection:
- Spine
- Near NV bundle
- Subcut (+/- tibia)

Question 5

Osteoblastoma
1. Age
2. Pain
3. Histo
4. Trt

Answer 5

Osteoblastoma
1. Age <30
2. Pain not relieved with NSAIDs (vs OO)
3. Histo - woven bone rimming NON malig osteoblasts (vs osteosarc)
4. Trt curettage

Question 6

Osteosarc
1. Where in the bone
2. Can arise from what systemic disease
3. Histo
4. Treat

Answer 6

Osteosarc
1. Metaphysis (for intraosseous)
2. Paget
3. Histo: woven bone w/ malig rimming osteoblasts (vs osteoblastoma)
4. Chemo - OR - chemo

Question 7

What tumor conditions are associated with osteosarcoma

Answer 7

Rb
p53 = Li Fraumeni

Question 8

Describe periosteal osteosarc - treat

Answer 8

From periosteum
Almost looks like a periosteal abscess on axial MR
OS: chemo - OR - chemo

Question 9

Describe parosteal osteosarc - treat

Answer 9

Stuck on
Painless, presents as mass effect
Low grade so wide resection ONLY

Question 10

Differential telangiectatic osteosarcoma from ABC

Answer 10

ABC = +USP6
Tel = fluid fluid levels but also destroying the bone

Question 11

Histo malignant fibrous histiocytoma

Answer 11

Form of osteosarcoma
Nests + glands
Looks like muscle - spindle cells

Question 12

Histo fibrosarcoma

Answer 12

Form of osteosarcoma
Herringbone