Bone Tumours

by Atikhah Shahirah

1) Regarding bone tumours:

a.	Primary bone tumours are considered more common than secondary tumours which metastases from other primary sites.	False
b.	Bone tumors in elderly persons are much more likely to be malignant.	True
c.	Most bone tumors arise without any previous known cause.	True
d.	Secondary osteosarcoma usually occur at metaphysis of distal femur, proximal tibia, and humerus	False

2) Regarding bone-forming tumours:

a.	Osteomas composed of woven and lamellar bone histologically	True
b.	Osteoid osteoma are larger in size than osteoblastoma and is not responsive to aspirin	False
c.	Osteosarcoma spread extensively in the medullary canal, infiltrating and replacing the marrow but only infrequently penetrating the epiphyseal plate or entering the joint space	True
d.	A triangular shadow on the x-ray film between the cortex and raised periosteum (Codman triangle) is characteristic of osteoid osteoma	False
e.	Osteosarcomas typically manifest as painful enlarging masses	True

3) Regarding cartilage-forming tumours:

a.	Inactivation of both copies of the EXT1 or EXT2 genes through mutation and loss of heterozygosity in chondrocytes of the growth plate is implicated in both sporadic and hereditary chondromas	False
b.	Osteochondromas usually arise in the short tubular bones of hands and feet.	False
c.	When chondroma arise on the bone surface, they are called juxtacortical chondromas	True
d.	Ollier disease is characterized by multiple chondromas preferentially involving one side of the body	True
e.	Chondrosarcomas preferred to metastases to lungs and skeleton	True

4) Regarding the fibrous and fibroosseous tumour:

a.	Larger lesions of fibrous cortical defects can develop into nonossifying fibromas.	True
b.	There are only two type of fibrous dysplasia which is monostotic; involvement of a single bone and polyostotic; involvement of multiple bones.	False
c.	In monostotic fibrous dysplasia, if the face or skull is involved, disfigurement can occur.	True
d.	Morphologically, fibrous dysplasia exhibits curved trabeculae of woven bone which mimicking Chinese characters.	True
e.	Polyostotic disease will transform into osteosarcoma, especially after radiotherapy.	False

5) Regarding miscellaneous bone tumour:

a)	Ewing sarcoma the second most common pediatric bone sarcoma after osteosarcoma.	True
b)	Ewing sarcoma demonstrate clear neural differentiation, whereas Primitive neuroectodermal tumors(PNET) are undifferentiated.	False
c)	More girls are affected with Ewing sarcoma compared to boys.	False
d)	Homer-Wright Rosettes are tumour cells arranged in a circle about a fibrillary central space.	True
e)	Ewing sarcoma/PNET typically manifests as a painful enlarging mass in the diaphyses of long tubular bones (especially the femur) and the pelvic flat bones.	True