Skeletal AM Answers
1.
a. F
Desmoplastic fibroma is a locally aggressive, benign neoplasm of bone. It can be considered the intraosseous counterpart of the soft tissue desmoid tumor.
b. F
The most common site of occurence is the mandible
c. F
Broad local resection is the treatment of choice. The lesion is prone to recur with curretage.
D. T
2.
a. F
Ewings sarcoma is a tumor of young people, with the peak age of incidence being 15 years old.
b. T
This is thought to reflect the red marrow distribution of the two age groups.
c. F
In Ewings sarcoma, bone metastases are common, and usually ARE a lytic destructive process similar in appearance to the primary tumor.
d. T
3.
a. T
b. F
Achondroplasia is an autosomal dominant defect in endochondral bone formation (osteochondrodysplasia) which causes skeletal growth derived from cartilage to be shortened. The most significant shortening occurs in long tubular bones, cranial base, and spinal pedicles.
c. T
d. F
Hydrocephalus is a concern in 60% of patients with achondroplasia.
e. T
However, it's mode of inheritance is autosomal dominant.
4.
C
Thanatophoric dwarfism is the most common cause of fatal neonatal dwarfism. Features include cloverleaf skull, short ribs with small thoracic volume, small pedicles, and square iliac bones.
5.
a. T
b. T
c. F
d. F
The most common sites of involvement include the distal femur, the proximal tibia, and the humerus.
e. T
f. T
In the presence of a large soft tissue mass or enlargement of a previously stable lesion chondrosarcomatous transformation must be considered.