Bone Lesions simulating Primary Neoplasms

Question 1

Fibrous Cortical Defects involve fibrous tissue replacing bone. What are the symptoms and in who?

Answer 1

Asymptomatic in children < 2 yo

Question 2

What size are Fibrous Cortical Defects?

Answer 2

< 0.5 cm

Question 3

If Fibrous Cortical Defects are > 0.5 cm, what are they now?

Answer 3

Nonossifying Fibroma

Question 4

How do Fibrous Cortical Defects/Nonossifying Fibromas look?

Answer 4

Radiolucent with thin rim of sclerosis

Question 5

What histological pattern of fibroplasts is seen with Fibrous Cortical Defects/Nonossifying Fibromas?

Answer 5

Fibroblasts in STORIFORM (pinwheel) pattern

Question 6

Treatment for Fibrous Cortical Defects/Nonossifying Fibroma?

Answer 6

Spontaneously resolve

Question 7

Fibroblasts in a storiform pattern in asymptomatic kids < 2 yo

Answer 7

Fibrous Cortical Defect

Question 8

Fibrous Dysplasia

Answer 8

Proliferation of fibrous tissue and bone that DO NOT MATURE

Question 9

When does Fibrous Dysplasia occur?

Answer 9

Early adolescence with possible reactivation in pregnancy

Question 10

Proliferation of fibrous tissue and bone that does not mature

Answer 10

Fibrous Dysplasia

Question 11

What specific appearance does Fibrous Dysplasia have?

Answer 11

Ground Glass appearance

Question 12

Fibrous Dysplasia involves what mutations and when?

Answer 12

GNAS1 gain of function mutations in embryogenesis

Question 13

Fibrous Dysplasia involves what mutations?

Answer 13

GNAS1 gain of function mutations

Question 14

How does the trabeculae of woven bone look with Fibrous Dysplasia?

Answer 14

Curvilinear trabeculae

Question 15

Fibrous Dysplasia involves intramedullary lytic lesions that cause what?

Answer 15

Bowing and cortical thinning

Question 16

What are the 4 types of Fibrous Dysplasia?

Answer 16

1. Monostotic
2. Polyostotic
3. McCune-Albright
4. Mazabraud Syndrome

Question 17

Monostotic Fibrous Dysplasia

Answer 17

Single bone

= ASYMPTOMATIC

Question 18

Polyostotic Fibrous Dysplasia

Answer 18

Crippling deformities of craniofacial, shoulder and pelvis

Question 19

McCune-Albright Fibrous Dysplasia

Answer 19

Same sided bone lesions + Cafe au lait spots

Question 20

McCune-Albright Fibrous Dysplasia can be seen with what specific developmental abnormality?

Answer 20

Precocious Puberty in females (early)

= same sided bone lesions + cafe au lait spots

Question 21

Mazabraud Syndrome of Fibrous Dysplasia

Answer 21

• Skeletal deformities in childhood

- Soft tissue Myxomas (intramuscular) as adult

Question 22

What is most common form of Skeletal Malignancy?

Answer 22

Metastatic tumors

Question 23

Metastatic bone tumors in adults are likely from what 4 sources?

Answer 23

Prostate
Breast
Kidney
Lung

Question 24

Metastatic bone tumors in kids are likely from what 5 sources?

Answer 24

Neuroblastoma
Wilms tumor
Osteosarcoma
Ewing Sarcoma
Rhabdomyosarcoma

Question 25

Metastatic Bone tumors are usually multifocal except for what 2?

Answer 25

Kidney

Thyroid

Question 26

Metastatic bone tumors in the hands/feet are from what 3 sources?

Answer 26

Lung
Kidney
Colon

Question 27

What is a common source for blastic (bone forming) metastatic bone tumors?

Answer 27

Prostatic Adenocarcinoma

Question 28

Prostatic Adenocarcinomas are bone ____ metastatic bone tumors

Answer 28

Bone FORMING