Sarcoma

Question 1

FNCLCC Sarcoma histopathology grade depends on

Answer 1

FNCLc grading depends on
1. Cell differentiation
2. Mitotic activity
3. Extent of necrosis

Question 2

Inrease risk of local recurrence in sarcoma

Answer 2

Increased risk of local recurrence in
1. Positive margin
2. Tumor site: RPS, H &N
3. Prior local recurrence
4. Age>50
5. Histology: FMS, desmoid, MPNST
Grade

Question 3

Common RT induced sarcoma are:

Answer 3

Common RT induced sarcoma are:
- Angiosarcoma: 21%
- Pleomorphic leiomyosarcoma
- Fibrosarcoma
- MPNST

Question 4

Histological classification of sarcoma

Answer 4

Fibroblastic/myofibroblastic tumor:
a. Malignant: adult fibrosarcoma, low grade fibromyxoid, myxofibrosarcoma, epitheliod
B. Fibrohistocytic tumor
a. Malignant: tensynovial giant cell tumor
C. Adipocytic tumor:
a. Malignant: liposarcoma
i. Dedifferentiated
ii. Myxoid
iii. Pleomorphic
D. Smooth muscle tumor
a. Leiomyosarcoma
E. Skeletal muscle tumor
a. Rhabdomyosarcoma
i. Alveolar
ii. Embryonal
iii. Pleomorphic
I : spindle cell
V: classic
F: vascular
G: perivascular: glomus tumor
H: neural: mpnst
J: GIST
K: uncertain differentiation:
Alveolar soft part sarcoma
Clear cell sarcoma
Desmoplastic
Epithelioid

Question 5

Histopathologic immunohistochemistry in sarcoma

Answer 5

CD34: dermato fibrosarcoma protuberance
CD99: ewing sarcoma family tumor
CD117: GIST
Synaptophysin and NSE: PNET, SMA
Vimentin, desmin= leiomyosarcoma, rhabdomyosarcoma

Question 6

Common D/D of STS below 30/20 years of age

Answer 6

RMS
ES
Desmoplastic
Alveolar
Clear cell and synovial

Question 7

STS D/D age >40/30

Answer 7

MFH
MPNST
DFSP
Fibrosarcoma
Leiomyosarcoma
Desmoid
Liposarcoma
MFH

Question 8

Common D/D of soft tissue sarcoma in abdomen

Answer 8

Midline abdomen: germ cell tumor, lymphoma
Lower abdomen: leiomyosarcoma, RMS
Extra abdominal: desmoid
Thigh: liposarcoma

Question 9

Common D/D of retroperitoneal mass

Answer 9

Germ cell tumor
Lymphoma
MFH
Kidney, GIST

Question 10

D/D of visceral STS

Answer 10

Leiomyosa
• Liposarcoma
• GIST
• Desmoid
• RMS, angiosarcoma
• Haemangiopericytoma

Question 11

Indication pre op RT in sarcoma

Answer 11

Indication of pre operative RT:
1. Borderline operable tumor to improve chance of R0 resection
2. Tumors with anticipated marginal resection (skull base, paranasal sinus, retroperitoneum)
3. Tumors close to neurovascular bundle
4. Situations where post OP Rt volume might leads significant late toxicities
5. RP/visceral sarcoma/ dedifferentiated/ myxoid round cell/LMS/MPNST)

Question 12

Post OP RT indication in sarcoma

Answer 12

Post OP RT: indication:
1. Large tumor >5cm
2. Deep seated tumor
3. High grade tumor (G2-3), margin positive even if <5cm
4. +ve margin: high grade
5. R1/R2 resection
6. Limb conserving wide excision/ limited surgery
7. Virtually all tumors in head and neck (because complete excision unlikely)
8. After surgery for recurrent sarcoma, if not previously irradiated.

Question 13

Soft tissue sarcoma radiotherapydose

Answer 13

Pre operative dose; 50 gy in 25 fractions
Post operative:
Elective ptv:50 gy in 25 daily fraction
Boost ptv: 10 gy in 5 daily fraction
Total dose: 60 gy in 30 daily fractions

Question 14

Prognostic factors of STS

Answer 14

Stage: I: 86%; II: 72%, III:52%
Grade
Tumor size and site
Histologic subtype
Tumor depth
Older age at presentation
Positive margin on resection
Bony oer neurovascular invasion
Gender
Race
Lymph node invovlement

Question 15

Common sarcoma in retroperitoneum: ajcc

Answer 15

Liposarcoma( well differentiated and dedifferentites)
Leiomyosarcoma
Less common
Pleomorphic lps
Undifferentiated Pleomorphic sarcoma
Mpnst
Solitary fibrous tumor

Question 16

Role of MRI in bone sarcoma

Answer 16

Marrow extention
• soft-tissue extension
• Relation with neuro-vascular bundle
• Skip lesion
• Whole-body MRI is a sensitive imaging technique for
the detection of skeletal metastases in patients with small cell neoplasms, Ewing sarcoma, and osteosarcoma