Soft-Tissue Tumors

Question 1

Describe in one or two sentences the classification scheme for mesenchymal/soft tissue tumors.

Answer 1

Using the T,N,M classification. Tumor characteristics, presence or absence of lymph node metastases, presence of absence of distant metastases.

Question 2

Describe the typical pattern of spread of sarcomas when they metastasize.

Answer 2

?

Question 3

State the type of cell that gives rise to soft tissue tumors.

Answer 3

Mesenchymal stem cells

Question 4

State the most common type of genetic abnormality in soft tissue tumors.

Answer 4

Translocations that can lead to fusion genes.

Question 5

State which factors are of prognostic importance for soft tissue tumors.

Answer 5

• Histologic classification: morphologic analysis is often complimented by immunohistochemical stains and cytogenetic analysis.
• Histologic grade is important for the prognosis for many types of sarcoma. Based on tumor differentiation score, mitotic count, and amount of tumor necrosis.
• Stage of the tumor determines both prognosis as well as chance of successful surgical excision.
• Tumors arising in superficial location (e.g. skin and subcutis) have a better prognosis than deep seated tumors. Size can also be a prognostic factor: in patients with deep-seated, high grade sarcomas, metastatic disease develops in 80% of those with a tumor larger than 20 cm and 30% of those with a tumor larger than 5 cm. Overall 10-year survival rate for sarcomas is approximately 40%.

Question 6

State which imaging modality is most helpful in the assessment of soft tissue tumors of the extremities.

Answer 6

MRI