Bone Tumors

Question 1

What are the 4 things that you should be aware of for bone tumors to make the dx easier?

Answer 1

1. age 2. sex 3. location 4. radiologic appearance of lesion

Question 2

What is fibrous dysplasia?

Answer 2

benign, localized developmental arrest, no maturity of bone even though bone is present * 3 patterns - polyostotic, monostotic and McCure Albright Syndrome (poly)

Question 3

What is McCure Albright syndrome?

Answer 3

cafe au lait skin pigmentation, endocrinpathies associated w/ this

Question 4

What does histo for fibrous dysplasia look like?

Answer 4

1. loose whorled pattern of fibroblastic tissue w/ irregular spicules of woven bone. 2. small islands of cartilage, chinese characters, poorly formed islets of bone. 3. Can undergo cystic degeneration.

Question 5

x-ray for fibrous dysplasia?

Answer 5

large expansile, apparently medullary mass with a somewhat moth-eaten appearance adjacent to it

Question 6

What is fibrous cortical defect?

Answer 6

1. Eccentric, sharply delineated, metaphyseal lesion in long bones of adolescents
2. usually occurs at metaphysis of femur and proximal tibia.
3. Spontaneously resolves.
4. 1/2 are bilateral or multiple, seen incidentally on xrays

Question 7

What is the appearance of fibrous cortical defect?

Answer 7

1. scooped out appearance w/ sclerotic margin.

Question 8

What is a nonossiffying fibroma?

Answer 8

a large fibrous cortical defect (> 5/6 cm)

Question 9

What is characteristic of nonossifying fibroma?

Answer 9

woven mat or storiform pattern

Question 10

What are solitary bone cysts?

Answer 10

1. benign fluid filled cysts
2. thin, lytic bone lesions in males
3. humerus/femur
4. asymtompatic
5. large lesion can lead to a fracture

Question 11

What are aneurysmal bone cysts?

Answer 11

1. bloody, cystic lesions
2. usually in long bones/vertebral column,
3. lesion is from the surface of the bone
4. slow growing but can rapidly expand

Question 12

This is aneurysmal bone cyst. What can be found in microscopic pathology?

Answer 12

1. clotted blood
2. giant cells – dont’ misDx giant cell tumor or TB

Question 13

Tell me about benign bone neoplasms

Answer 13

1. happens in 1st 3 decades in life mostly
2. found on incidental xrays
3. rarely undergo malignant transformation EXCEPT CHONDROMA
4. usually removed only if cause pain
5. examples : Osteoma, osteoid osteoma, osteochrondroma/chondroma, fibroma, giant cell tumor

Question 14

What is an osteoma?

Answer 14

1. round, projects from sub/endosteal surface of cortex
2. slow growing
3. usually solitary, mutiple seen in Gardner’s syndrome

Question 15

What is osteoid osteoma?

Answer 15

1. one of the more common representations of osteoma
2. generally less than 2 cm
3. teens/20’s – MALES
4. 50% - in tibia/fibula

Question 16

What is a primary characteristic of osteoid osteoma?

Answer 16

1. Painful due to lesion making PGE2
2. pain is more common at night, relieved by aspirin and alcohol

Question 17

What is osteochrondroma?

Answer 17

1. also known as exostosis
2. cartilage capped tumor – attached to underlying skeleton by stalk
3. grows proximally to epiphyseal plate

Question 18

What is osteochrondoma due to?

Answer 18

1. displacement of growth plate in endochrondal bones
2. you can have a multiple hereditary exotosis which is AD and can give rise to chondrosarcoma

Question 19

What is a chrondroma?

Answer 19

1. hyaline cartilage tumor

Question 20

What are the 2 types of chrondromas?

Answer 20

1. endochrondroma - arises in medullary cavity
2. juxtacortical - arises on surface of bones

Question 21

Where is an endochrondroma usually found?

Answer 21

1. Metaphyses of tubular bones: hands/feet – usually solitary
2. here is a pic of a phalanx - radiolucent nodules of hyaline cartilage scalloped endosteal surface

Question 22

What is it called when endochrondromas present w/ mutiple lesions?

Answer 22

1. Ollier dz - nonhereditary syndrome
2. Muffucci Syndrome - multiple enchondromas form as well as soft tissue hemangiomas

Question 23

What is Giant Cell Tumor of Bone?

Answer 23

1. multinucleated osteoclast type giant cells that are locally aggressive
2. cystic degeneration

Question 24

where is giant cell tumor of bone normally found?

Answer 24

in knee than bones of wrist.

* here is a pic of a soft, hazy neoplasm which appears to be destroying the distal femur

Question 25

tell me about malignant bone tumors

Answer 25

1. rare 2. 50% from blood forming cells and CT cells 3. Mets are more common than primary bone tumors

Question 26

What is most common primary malignant bone tumor and where is it found in the body?

Answer 26

Osteosarcoma -- in knee \* smaller peak of these in the elderly, in patients who have Paget disease of bone

Question 27

What is 2nd most common primary malignant bone tumor and where is it found in the body?

Answer 27

chrondrosarcoma -- trunk and limb girdles

Question 28

What else has osteosarcoma been associated with?

Answer 28

1. Retinoblastoma 2. 20% have lung mets at time of dx 3. Painful, progressively enlarging; fracture

Question 29

What is seen microscopically in osteosarcoma?

Answer 29

poorly formed bone spicules in between which is a cellular matrix with osteoid and malignant cells

Question 30

What is characteristic of an osteosarcoma? --- BOARD QUESTION!

Answer 30

periosteal elevation on x-ray = Codman's triangle

Question 31

What is chondrosarcoma?

Answer 31

1. occur in the axial skeleton, characteristically in the trunk, pelvis, vertebrae and ribs 2. May arise in association with preexisting enchondroma 3. 35-60 4. Rx = SURGERY

Question 32

What is characteristic of malignant bone tumor?

Answer 32

bulk of tumor is distal and some is proximal meaning that it doesn't respect the joint spaces

Question 33

This is a chondrosarcoma - what do the cells look like at this level and what would they look like at a higher power?

Answer 33

1. cellular neoplasm - mimic chondrocytes 2. at higher power - look like malignant cells w/ high N:C ratio, nuclei, and mitotic figures

Question 34

What is Ewing Sarcoma?

Answer 34

1. small, round blue cell tumor 2. 10-15 yr, white 2. arise in medulla of bone - diaphysis of long joints 4. good prognosis - srugery and chemo!

Question 35

What cancer is this and what are you supposed to see in these cells?

Answer 35

1. Ewing Sarcoma 2. glycogen rich 3. Homer-Wright Rosettes - tumor cells arranged in a circle about a central fibrillary space -- possibly neural differentiation

Question 36

What do you see on xray for Ewing sarcoma -- also what is the translocation?

Answer 36

1. onion skin -- layers of reactive perisoteum 2. 11;22

Question 37

Tell me about bone Met tumors

Answer 37

1. Adults \> 75% of skeletal metastasis originate from prostate, breast, lung, and kidney • Kids: neuroblastoma, Wilms’ tumor, osteosarcoma, Ewing sarcoma (extraosseous) and rhabdomyosarcoma • Usually multifocal: vertebrae, pelvis, ribs, skull and sternum (marrow-rich areas) • XR: lytic, blastic or mixed lytic and blastic • Secrete substances that promote bone resorption