Tumors of Bone and Cartilage - Gupta

Question 1

What are the tumors of bone?

Answer 1

1) Osteoma
2) Osteoid osteoma/osteoblastoma
3) Osteosarcoma

Question 2

What is an osteoma?

Answer 2

Benign bone forming tumor composed of compact or mature trabecular bone –> usually involves facial bones

Question 3

What is the clinical presentation of a pt with osteoma?

Answer 3

1) Pain
2) Headache
3) Vision changes

Associated with Gardner syndrome (familial colorectal polyposis)

Question 4

What is the microscopic appearance of an osteoma?

Answer 4

Dense compact bone with paucicellular stroma (see very few cells)

Question 5

What is Gardner syndrome?

Answer 5

Autosomal dominant (chromosome 5q21 - APC gene) disease leading to multiple colon polyps and tumors in thyroid, bone, epidermoid cysts, fibromas, and desmoid tumors

Question 6

What are desmoid tumors?

Answer 6

Tumors that grow in b/t muscle fibers and can cause obstruction –> surgical resection causes more tumors to form

Question 7

What is osteoid osteoma?

Answer 7

Benign tumor of osteoblasts

Question 8

What population are osteoid osteomas seen in?

Answer 8

Males < 25 years old

Question 9

What is the clinical presentation of osteoid osteoma?

Answer 9

Bone pain that resolves with aspirin

Question 10

What is the microscopic appearance of osteoid osteoma?

Answer 10

Randomly interconnected trabeculae of woven bone, prominently rimmed by a single cell layer of osteoblasts

Question 11

Where do osteoid osteomas occur and what do they look like on imaging?

Answer 11

Cortex of long bones

Bony mass (<2cm) with radiolucent center (osteoid, black arrow) with surrounding sclerosis (white arrow)

Question 12

How does osteoblastoma differ from osteoid osteoma?

Answer 12

Osteoblastoma usually larger (>2cm)

Bone pain doesn’t respond to aspirin

Arise in the vertebrae

Question 13

What does osteoblastoma look like microscopically?

Answer 13

Comprised of anastomosing trabeculae of osteoid and woven bone rimmed by osteoblasts

Question 14

How is osteoblastoma treated?

Answer 14

Curettage (scooping) or excision en bloc

Question 15

What is osteosarcoma?

Answer 15

Malignant prolferation of osteoblasts

Question 16

What is the epidemiology of osteosarcoma?

Answer 16

Mostly in teenage males

Associated with Pagets disease and post-radiation in elderly

Rb gene = increased risk and poor prognosis

Question 17

What characteristic feature does osteosarcoma show on imaging?

Answer 17

Codman’s triangle –> periosteol reaction to tumor destroying new bone before it ossifies

Indicates aggresive tumor

Question 18

What does osteosarcoma look like microscopically?

Answer 18

Invades normal bone producing poorly formed bony spicules in a hypercellular matrix of osteoid and numerous pleomorphic malignant cells

Described as “lace-like” –> dainty little tumors

Question 19

What is seen in chondroblastic osteosarcoma?

Answer 19

Malignant cartilage formation

Question 20

What is the pathogenesis of osteosarcoma?

Answer 20

70% have acquired genetic mutation

Rb –> germline Rb 1000x increased risk

TP53 –> DNA repair and apoptosis

INK4a –> encodes tumor suppressor

MDM2 and CDK4 –> cell cycle regulators that inhibit p53 and Rb

Question 21

What are the cartilage-forming tumors?

Answer 21

1) Chondroma
2) Osteochondroma
3) Chondrosarcoma

Question 22

What is a chondroma?

What are the types of chondroma?

Answer 22

Benign cartilaginous tumor

1) Enchondroma –> arises from diaphyseal medullary cavity
2) Subperiosteal/juxtacortical
3) Soft tissue chondroma

Question 23

What genetic mutations are associated with enchondromas?

Answer 23

IDH1 and IDH2 (isocitrate dehydrogenase)

Question 24

What does a chondroma look like grossly?

Answer 24

Grey-white mass with color consistent with cartilage –> usually well circumscribed

Question 25

What does chondroma look like microscopically?

Answer 25

Numerous chondrocytes closely packed near periphery in a pink ground substance that resembles normal cartilage

Question 26

What is an osteochondroma?

Answer 26

Tumor of bone with an overlying cartilage cap --\> mushroom cap appearance on X-ray is pathognomonic

Question 27

What is the epidemiology of osteochondroma?

Answer 27

Mostly in males 10-20 years old

Question 28

What is the epidemiology and location of enchondroma?

Answer 28

Age 20-49, no gender preference Usually found in small bones of hands and feet

Question 29

What is Maffuci syndrome?

Answer 29

Multiple enchondromas and soft tissue hemangiomas; also ovarian carcinoma and brain glioma

Question 30

What is chondrosarcoma and where is it typically found?

Answer 30

Malignant cartilage forming tumor (no osteoid) Arises in medulla of pelvis or central/axial skeleton

Question 31

What is the epidemiology of chondrosarcoma?

Answer 31

Men in their 40s

Question 32

What is the gross appearance of chondrosarcoma?

Answer 32

Invasive cartilage growth in bone This example shows cartilage growing across joint space

Question 33

What is the microscopic appearance of chondrosarcoma?

Answer 33

Cells mimic normal chondrocytes --\> appear to float in chondroid-like matrix

Question 34

What are the fibrous and fibroosseous tumors?

Answer 34

1) Fibrous cortical defect 2) Fibrous dysplasia

Question 35

What is a fibrous cortical defect (nonossifying fibroma)?

Answer 35

Benign fibrous lesion of bone

Question 36

What is the epidemiology of fibrous cortical defect?

Answer 36

Children and adolescents

Question 37

What is the microscopic appearance of fibrous cortical defect?

Answer 37

Fibrous spindle cells with pinwheel appearance Scattered giant cells, histiocytes, cholesterol clefts, and hemosiderin

Question 38

What does fibrous cortical defect look like grossly?

Answer 38

Lesion \>5cm with intermedullary component

Question 39

What is fibrous dysplasia?

Answer 39

A problem with osteoblastic maturation that causes fibrous tissue to form instead of medullary bone

Question 40

How does fibrous dysplasia present and what are the most common sites?

Answer 40

Presents with painful swollen bones prone to fracture Ribs and femur are most commonly affected

Question 41

What is the gross appearance of fibrous dysplasia?

Answer 41

Variable size, well circumscribed, _medullary_, tan-white, gritty mass lesions

Question 42

What is the microscopic appearance of fibrous dysplasia?

Answer 42

Poorly formed islets of trabeculae of woven bone without a rim of osteoblasts --\> resemble chinese characters Fibroblastic activity surrounding trabeculae with lots of collagen

Question 43

What is McCune-Albright syndrome?

Answer 43

Fibrous dysplasia plus cafe-au-laite spots and endocrine dysfuntion (especially early onset puberty)

Question 44

What is a giant cell tumor of bone?

Answer 44

Tumor composed of multinucleated giant cells and stromal cells

Question 45

What is the epidemiology of giant cell tumor of bone and where does it typically arise?

Answer 45

Young adults (20-40) Epiphysis of long bones, typically in the knee

Question 46

What is the characterstic appearance of giant cell tumor on X-ray?

Answer 46

"Soap bubble" appearance --\> dude is fucked

Question 47

What feature of giant cell tumor cells makes them a good candidate for targeted therapy?

Answer 47

High level of RANK-L expression

Question 48

What is the microscopic appearance of giant cell tumor?

Answer 48

Regular and uniform distribution of stromal and giant cells --\> nuclei of mononuclear cells and osteoclasts are ovoid with prominent nucleoli (top pic) Fibroblastic activity and formation of reactive bone (bottom pic, pink shit)

Question 49

What is Ewing sarcoma (primitive neuroectodermal tumor)?

Answer 49

Malignant proliferation of poorly-differentiated cells derived from neuroectoderm

Question 50

What is the epidemiology and typical location of Ewing sarcoma?

Answer 50

Usually in males \<15 years old Typically found in diaphysis of long bones

Question 51

What is the gross appearance of Ewing sarcoma?

Answer 51

White, fleshy, ill-defined tumor with involvement of medulla and cortex with periosteal elevation

Question 52

What is the microscopic appearance of Ewing sarcoma?

Answer 52

Sheets of small, round, uniform cells (resemble lymphocytes) Indistinct cell membranes

Question 53

What is the characteristic appearance of Ewing sarcoma on X-ray?

Answer 53

Onion skin appearance of periosteum - layered periosteum

Question 54

What translocation is seen in Ewing sarcoma?

Answer 54

t(11,22) EWS-FLI1 fusion

Question 55

What cellular organization pattern is sometimes seen in Ewing sarcoma?

Answer 55

Homer Wright rosettes --\> dark blue tumor cells surrounding pink fibrillar material resembling neuropil

Question 56

What is a solitary bone cyst?

Answer 56

Benign lytic lesion, fluid-filled cyst with a thin wall

Question 57

What is the epidemiology and typical location of solitary bone cysts?

Answer 57

Males \<20 years old Medullary in metaphysis of proximal humerus or femur --\> typicaly presents as a fracture

Question 58

What is an anuerysmal bone cyst?

Answer 58

Exactly what is sounds like asshole Benign, but grows rapidly Looks like a sponge filled with blood

Question 59

What is the epidemiology of anuerysmal bone cysts?

Answer 59

No gender preference; ages 1-20 Removed by curettage

Question 60

What is the microscopic appearance of anuerysmal bone cysts?

Answer 60

Richly vascularized bone tissue --\> differentiating feature is rich capillary bed

Question 61

What do metastatic bone tumors do to bone? What is the exception?

Answer 61

Produce punched out lesions radiographically **Prostatic carcinoma** produces osteoblastic (sclerotic) lesions

Question 62

What is the mnemonic to remember sites of metastasis for bone shit

Answer 62

**BLT** with a **K**osher **P**ickle Breast Lung Thyroid Kidney Prostate

Question 63

Whats does metastatic bone tumor from prostatic carcinoma look like radiographically?

Answer 63

Osteoblastic lesions --\> highly sclerotic bone