Intramedullary Osteosarcoma

Question 1

describe

Answer 1

MC primary sarcoma of bone

• MC malig of bone is mets
• MC prim malig of bone is myeloma

Question 2

age

Answer 2

children adolescents

Question 3

location

Answer 3

MC is distal femur and prox tibia

-other common-prox humerus, prox femur, and pelvis

Question 4

malig

Answer 4

MC stage IIB (high grade, extra-compartmental, no mets

• 10-20% of pts present pulm mets
• bone is 2nd MC

Question 5

Genetics

Answer 5

-Retinoblastoma tumor supressor gene (Rb) predisposed

Question 6

rothmund thomson syndrome

Answer 6

AR inheritance, mutations RECQL4, chr 8q24.3

Question 7

Poor Prognostic Factors

Answer 7

advance stage of dz, response to chemo, tumor site and size, expression of P-glycoprotein, high serum alk phos, high lactic dehydrogenase, vascular involvment, surgical margins, type of chemo regimen

Question 8

symptoms

Answer 8

rapidly progressive pain, fever, and swelling

Question 9

Imaging

Answer 9

characteristic blastic and destructive lesion (sun-burst or hair on end pattern of matrix mineralization)
-periosteal reaction (Codman’s triangle)

Question 10

Labs

Answer 10

elevated alk phos