Bone Tumors (Week 3--Nelson)

Question 1

Bone tumors

Answer 1

Rare

They are mesenchymal tumors and mesenchymal tumors don’t follow the normal dysplasia –> carcinoma in situ –> carcinoma pattern

Must have clinical and radiological correlation

Question 2

Primary bone tumor

Answer 2

Primary bone tumor (start in the bone) that is malignant is called a sarcoma

This is NOT cancer that has metastasized (ie breast cancer metastatic to bone is NOT bone cancer!)

Also, this is NOT bone marrow/hematopoietic cancer

Question 3

Malignant bone tumors

Answer 3

De novo malignant tumor (don’t know what caused it)

From benign to malignant

Secondary from radiation

Question 4

Malignant primary bone tumors

Answer 4

Very rare (<.01% of malignancies)

Aggressive

Hematogenous spread of sarcomas (conversely, remember carcinomas go through lymphatics)

Correct diagnosis depends on clinical history, radiographic studies, histology

Question 5

Osteosarcoma

Answer 5

“The mother of all bone tumors”

Most common primary malignant bone tumor

Two peaks: 10-20 (KIDS) and 60-70

Pain and swelling

Different types and grades of osteosarcoma

Pathogenesis not understood in most cases

Known to follow radiation, Paget’s disease

Most common in long bones, metaphysis (KNEE) (but can also be in other places like craniofacial, small bones, extraskeletal (soft tissue))

Aggressive, fatal disease

Question 6

Osteosarcoma on radiology

Answer 6

Malignant appearance

Infiltrative, destructive

Blastic, mineralized

Codman’s triangle, sunburst pattern (STEP 1)

Question 7

Osteosarcoma gross pathology

Answer 7

Filling medullary portion, breaking through cortex, extending into soft tissue

Question 8

Osteosarcoma histology

Answer 8

Plump neoplastic osteblasts

Delicate, immature osteoid production (these tumors make bone)

Infiltration and destruction of normal bone

Question 9

Variants of osteosarcoma

Answer 9

Not important what they are!

Osteoblastic

Chondroblastic

Telangiectatic

Small cell

Low grade intramedullary

Periosteal

Parosteal

Fibroblastic

Dedifferentiated

Giant cell rich

Chondroblastoma-like

Osteoblastoma-like

Intracortical low-grade

Etc…

Question 10

When does it not matter what specific variant the osteosarcoma is?

Answer 10

When the osteosarcoma is high grade, it doesn’t matter what the specific variant is

Most ARE high grade!

Question 11

Where can osteosarcoma spread to?

Answer 11

Lungs, just like many other sarcomas

Question 12

Osteosarcoma treatment and prognosis

Answer 12

Treatment: chemotherapy (at least 3 types, high grade), excision, rarely do amputations anymore

Prognosis: 60-75% 5 year survival (much improved)

Question 13

Chondrosarcoma

Answer 13

Second most common primary bone tumor (after osteosarcoma)

Chondro = cartilage

Adults age 40-60

Pelvis, flat bones, only sometimes in long bones

Usually de novo

Can be from osteochondroma

Most are grade I (low grade), but can be grade II or III

Low grade may “dedifferentiate” into high grade sarcoma

Question 14

Chondrosarcoma on radiology

Answer 14

Lobulated

Destructive mass with calcification

Question 15

Chondrosarcoma gross pathology

Answer 15

Lobulated

Destructive

White/translucent

Calcified

Question 16

Chondrosarcoma histology

Answer 16

Lobules of cartilage

Permeating bone (invasive)

Calcification

Question 17

Chondrosarcoma treatment

Answer 17

Excision

Generally NOT chemotherapy sensitive

Question 18

Ewing Sarcoma/PNET

Answer 18

A member of the Primitive Neuroectodermal Tumor (PNET) family

11:22 translocation

Usually in children

Diaphyseal (long tubular part of the bone)

Present as pain, mass

May be very rapidly growing

Question 19

Ewing sarcoma/PNET on radiology

Answer 19

Lucent lesion with reactive bone formation, edema

Looks much like osteomyelitis, LCG

Spiculated?

Question 20

Ewing sarcoma/PNET histology

Answer 20

Malignant small blue round cells

High mitotic rate

Geographic necrosis

Special tests help: cytogenetics, IHC

Question 21

Ewing sarcoma/PNET treatment and prognosis

Answer 21

Chemotherapy

Radiation therapy

Surgical excision

Prognosis: improving, to 60%

Question 22

Chordoma

Answer 22

Adult tumor

Usually in sacrum, spine

Presents as a mass with bone destruction

Thought to be from notochord remnants

Malignant

Question 23

Chordoma on radiology

Answer 23

Expansile lesion

Destroying bone and extending into soft tissue

Question 24

Chordoma gross pathology

Answer 24

Lobulated

Myxoid

Question 25

Chordoma histology

Answer 25

**Cords** of cells in loose **myxoid** matrix **Bubbly "physaliphorous" cells**

Question 26

Chordoma treatment and prognosis

Answer 26

Treatment: **excision** Prognosis: high **recurrance** rate, **intermediate metastatic potential**

Question 27

Transformation

Answer 27

Benign primary bone tumors transform to malignant forms

Question 28

Fibrous dysplasia

Answer 28

**Benign** **expansile** bone tumor **Long bones, facial bones** Can **transform** to **osetosarcoma** (bad!)

Question 29

Osteochondroma transformation to secondary chondrosarcoma

Answer 29

**Osteochondroma** is **benign** But 10% chance of malignant change to **chondrosarcoma**

Question 30

Giant cell tumor

Answer 30

**Benign** **Epiphyseal** tumor of **adults** (skeletally mature) **Need to rule out hyperparathyroidism**, which causes identical "brown tumor"

Question 31

Giant cell tumor on radiology

Answer 31

**Lucent**, **destructive** mass in epiphysis

Question 32

Giant cell tumor treatment and prognosis

Answer 32

Treatment: **curettage**, **excision** Prognosis: **20% recurrance** rate, but only **rarely** malignant transformation

Question 33

Malignant giant cell tumor

Answer 33

**Rare** transformation to malignancy Turns to **high grade** sarcoma Most common **following radiation therapy** for benign giant cell tumor May occur **de novo**

Question 34

Plasmacytoma

Answer 34

Tumor of **malignant plasma cells** If there are multiple, then **multiple myeloma** **Monoclonal immunoglobulin** spike in SEP Atypical plasma cells

Question 35

Plasmacytoma on radiology

Answer 35

**Punched out lesions** **Lytic**

Question 36

Cancers that metastasize to bone

Answer 36

Breast Renal Thyroid Prostate Most common "bone" tumor Treatment is curettage, fixation (hardware) Often present with **pain** or **pathologic fracture**

Question 37

Clinical information important in diagnosing bone tumors

Answer 37

**Age** **Presentation** (time period) **Radiographic** **Location** (epiphysis, metaphysis, diaphysis, etc)

Question 38

Where do we look for metastasis of bone cancer?

Answer 38

Metastasize from leg bones to **lungs**, so look in lungs

Question 39

Why would osteosarcoma be mistaken for a reactive process?

Answer 39

Because both processes are **laying down immature bone**