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.
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.
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)
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
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
30.
31.
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.