B bone tumor 3

Question 1

Simple Bone Cyst

true cyst of bone- fluid filled caity lined with endothelia and fibruous tissue

younger age associated with more aggressive lesion

◦Asymptomatic unless pathological fracture

not common in the knee

possible spntaneous resolution

Answer 1

Unicameral Bone Cyst

Question 2

Geographic lesion

Mildly expansile

• No wider than physis

Sharp zone of transition

Sclerotic margin

“Empty” appearing matrix

Answer 2

Unicameral Bone Cyst

Question 3

Metaphyseal location

“Active” lesions maintain position adjacent to physeal plate

Latent” lesions “drift away” from physeal plate to metadiaphysis

Internal scalloping of cortex may create false “septations”

treatment- curretage and pack

Answer 3

Unicameral Bone Cyst

Question 4

◦“Fallen fragment” sign may be seen if fx’d

Answer 4

Unicameral Bone Cyst

Question 5

Lesions typically asymptomatic, transient and self-resolving

Sites: long bones

Location- Metaphyseal/metadiaphyseal

◦ - Juxtacortical location

Shape/Size

• Ovoid, oriented along long axis of bone
• Most in the 0.5 – 3 cm. Range

Sclerotic, scalloped margin; well-defined

Answer 5

Benign Fibrous Cortical Defect

Question 6

Juxtacortical location

Long axis of lesion aligns with long axis of bone

Sclerotic margins, often smoothly scalloped

Answer 6

Benign Fibrous Cortical Defect

Question 7

fibroxanthoma two similar lesions

Answer 7

benign fibrous cortical defect

Non-ossifying Fibroma of Bone

Question 8

Non-ossifying Fibroma of Bone similar to:

Answer 8

Benign fibrous cortical defect

larger

more likely to persist

more involvement of central portion of bone

weaken bones

Question 9

3 presentations of Fibrous Dysplasia

Answer 9

◦Monostotic: most common (75% cases)- ?more?

◦Polyostotic: approx. 25%

◦Polyostotic with assoc. endocrine anomaly (rare)

Many cases are asymptomatic and incidentally noted on x-ray exam

idiopathic

Question 10

◦Lytic, geographic with sclerotic border

◦Sclerotic

◦Mixed, “disorganized” appearance of matrix

Bone expansion common with intact cortex

◦Thinned maybe, but not destroyed

◦May path fracture

No periosteal rx’n or soft tissue mass

Answer 10

Fibrous Dysplasia

Question 11

Answer 11

Fibrous Dysplasia

Question 12

Answer 12

Fibrous Dysplasia

not common in the ribs

Question 13

Answer 13

Fibrous Dysplasia

Question 14

Answer 14

Fibrous Dysplasia

Question 15

Answer 15

Fibrous Dysplasia

Question 16

Answer 16

Polyostotic Fibrous Dysplasia

Question 17

when in the hand it mimics olliers disease

Answer 17

Polyostotic Fibrous Dysplasia

Question 18

Answer 18

Polyostotic Fibrous Dysplasia

Question 19

Histologically a type of A-V malformation, not a true cyst.

May develop as a primary lesion, or secondary to a pre-existing lesion

◦Some authors feel almost all are secondary

Age- adolescent to young adult most common

◦80% occur below age 20

Typically mild pain with hx over mos.-yrs.

Answer 19

Aneurysmal Bone Cyst

Question 20

Sites – 80% long bone metaphyses or post. arch

◦One of three most benign posterior arch lesions of spine

Location in long bones- typically metaphyseal and eccentrically placed

Expansile (often marked), geographic lesion

Cortex may be thinned to imperceptible- can mimic “blowout” type metastatic lesion

Treated with curretage/packing- may reoccur

Answer 20

Aneurysmal Bone Cyst

Question 21

Answer 21

Aneurysmal Bone Cyst

Question 22

Answer 22

Aneurysmal Bone Cyst