This document discusses two types of soft tissue sarcomas: mesenchymal chondrosarcoma and synovial sarcoma. Both tumor types contain soft tissue components, calcified areas, mineralization, and cystic areas or necrosis/hemorrhage. Mesenchymal chondrosarcoma has a bimodal age distribution in the 3rd and 5th decades, while synovial sarcoma typically presents between 15-50 years of age, with a mean of 35 years. The tumors can arise in soft tissues near joints. Imaging findings include soft tissue masses with mineralization or calcification that demonstrate enhancement. Histopathological examination is needed for definitive diagnosis of each tumor type.

1. Mesenchymal
Chondrosarcoma
Dr. Manmohan Bir Shrestha
Radiology & ImagingFOR RADIOLOGY

2. Extraskeletal Mesenchymal Chondrosarcoma
Synovial Sarcoma

4. Chondrosarcoma
2nd most frequent primary malignant tumor of bone.
of cartilaginous origin
tumor matrix formation is entirely chondroid in nature.
2 Extraskeletal varieties (attributes 2 % of all soft tissue
sarcomas)
Myxoid
Mesenchymal

5. Extraskeletal Mesenchymal Chondrosarcoma
Rare
50% arise in soft tissues
Sex Prevalence – M:F= 1:1
Bimodal age distribution
3rd decade
Tumors of head & neck
Common in meninges & periorbital region
5th decade
Tumors of thigh, trunk & calf

6. Clinical feature
Localized swelling, slow-growing but some has
aggressive nature
Localized pain
Joint immobility if near joint
Some patient may present with metastases

7. Histology
More or less differentiated cartilage cells
Proliferation of small mesenchymal cells
Hemangiopericytoma like vascular pattern
Metastases
 to lungs & lymph nodes.

8. Plain radiograph & CT Scan
Soft tissue mass with matrix mineralization
(50-100%) rings +arcs/flocculent
+ stippled calcification/dense mineralization

9. MRI
T1WI – isointense to muscle
T2WI – fat signal intensity
Signal voids from calcification
After contrast – homogenous/heterogenous
enhancement
Radionuclide scan
Increased vascularity in blood pool phase.

10. Hard mass in middle-aged man’s calf for 8 years

13. T1 Contrast + shows Extraskeletal Mesenchymal Chondrosarcoma

14. Treatment
Surgical resection
Chemotherapy
Radiotherapy
Prognosis
25% 10 year survival rate

16. Synovial Sarcoma
Definition :
Slow growing expansile malignant tumor originating with
extensive malignant potential.
Synonyms :
Malignant Synovioma
Tendosynovial Sarcoma
Synovioblastic Sarcoma
Synovial Endothelioma

17. Incidence :
4th most common soft tissue sarcoma
(after malignant fibrous histiocytoma,
liposarcoma and rhabdomyosarcoma)
2-10% of all primary malignancies worldwide.
Age : Mean age 35 yrs.
(84% between 15-50 yrs. )
Sex : M/F = 1-1.2/1

18. Site :
 in synovial lining/bursa /tendon sheath adjacent to joint
 Uncommonly intraarticular (5-10%)
 arise near joints, it is rare for them to arise from the joint itself and
despite their name, they do not arise from synovial structures, e.g.
joints, tendon sheaths and bursae.
Location :
 Lower extremity (2/3rd 0f the cases)
 Popliteal fossa, hip, foot & ankle
 Upper extremity (1/3rd of the cases)
 Elbow, wrist & hands.
 Pelvis (8%)
 Trunk (7%)
 Head & neck (5%)
 Retroperitoneum(0.3%)

19. Clinical features
 Slow growing Soft tissue mass or
swelling associated with local pain.
 Metastases present in 16-25% at presentation.
(can cause cannon ball metastases to lungs)

20. Imaging modalities
Plain x-ray
CT scan
MRI
USG
Radionuclide scanning

21. Plain X-ray
Large spheroid well-defined soft tissue mass.
Amorphous punctate calcification/ ossification (often eccentric
or peripheral )
Involvement of adjacent bone (11-20%)
Periosteal reaction
Invasion of cortex with wide zone of transition
Juxta articular osteoporosis
Lesion about 1 cm away from joint cartilage
*** Calcifications in other soft-tissue sarcomas are uncommon

22. X-ray right knee 25 yrs. male

23. Extensively calcified
synovial sarcoma in a 36-
year-old woman

24. USG
Round/lobulated hypoechoic solid soft tissue mass
Heterogenous textures with irregular margins

25. Transverse USG over proximal
tibia- Irregular solid lesion
abutting distal end of iliotibial
tract with echogenic foci which
represents calcifications

26. CT Scan
Heterogeneous deep seated multinodular soft tissue mass
with attenuation slightly less than muscle.
Multinodular morphology with well-defined (53%)/ irregular
(47%) margins.
Areas of lower attenuation represent necrosis / hemorrhage.
Calcifications(27-41%)
Bone erosion/ marrow invasion.(25%)
Heterogeneous enhancement (89-100%)

27. MRI
T1WI -Prominently heterogeneous soft-tissue mass
with signal intensity similar to or slightly higher than
muscle.
Triple sign on T2WI in 35-57%
Hypo –calcified/fibrotic tissue
Iso – solid cellular elements
Hyper – hemorrhage/necrosis
Fluid-fluid levels due to previous hemorrhage.
Bone marrow invasion /Cortical erosion (21%)
Neurovascular encasement

28. Contrast Enhanced MRI
 Prominent heterogeneous (83%)/homogeneous enhancement(17%)
 Peripheral / Nodular enhancement for necrotic tissue
 Serpentine vascular channels.
 Initially rapid progressive increase in signal intensity followed by wash
out(60%) / late sustained increase (40%)

29. 20 yrs. female with left hip pain , x-ray shows lucency over left greater
trochanter

32. Radionuclide Scan
Prominently increased uptake in blood flow & blood
pool phase.
Heterogeneous mild uptake due to mixture of viable
& necrotic tissue, perhaps associated with
calcification.

33. Metastases
 Lungs (94%)
 Lymph nodes (4-18%)
 Bone (8-11%)
* Metastasis is present in 16-25% cases at presentation.

34. Treatment
Local excision /amputation.
Radiotherapy.
Chemotherapy.

35. Prognosis
Local recurrence (30-50%)
5 yrs. survival rate (36-76%)
10 yrs. survival rate (20-63%)
Poor prognostic factors
Tumor size > 5 cm.
Presence of poorly differentiated areas.

36. Summary
Incidence
Synovial sarcoma > Mesenchymal Chondrosarcoma.
Contents (Both)
Soft tissue component
Calcified areas
Mineralization
Cystic areas
Necrosis/hemorrhage
Site
Around joints or soft tissue
Age
Mesenchymal chondrosarcoma bimodal (3rd & 5th decade)
Synovial Sarcoma (15-50, mean 35 years)
Histopathological differentiation remains specific

37. Presenting caseX-ray
T1 T2
PD T1 C+ GRE