Soft tissue sarcoma is a rare and heterogeneous group of tumors that arise from mesenchymal tissues. It accounts for less than 1% of all cancers. The extremities are the most common primary site. Complete surgical excision with negative margins is the standard treatment, but adjuvant radiation and/or chemotherapy may be used depending on factors like tumor size, grade, and margins. Prognosis depends on tumor size, grade, depth, and whether there is local or distant spread.

1. Soft tissue sarcoma
Presented by
Dr Dipendra Maharjan

2. Introduction
 Rare and heterogeneous
group of tumors
 Mesenchymal origin
 <1% of all cancers
 Dozens of subtypes
 Classified as per the
purported cell of origin or
resemblance
Vodanovich DA, Choong PF. Soft-tissue sarcomas. Indian journal of orthopaedics. 2018 Feb;52:35-44.

3.  STS predominate over bone sarcoma
 4:1
 Male preponderance for the incidence
 1.4:1
 Extremities are the most common site (40%)
 Lower limb being more common (28%)
 44% in thigh
Vodanovich DA, Choong PF. Soft-tissue sarcomas. Indian journal of orthopaedics. 2018 Feb;52:35-44.

4. Etiological factor
 Environment
 Trauma
 Chemical carcinogens
 Asbestos
 Surgical implants
 Radiation
 Viral infection
 HIV
 Cytomegalovirus
 Human Herpes virus
 Epstein Barr virus
• Genetic
– Neurofibromatosis
– Retinoblastoma
– Gardner’s syndrome
– Li-fraumeni syndrome
• Immunologic
– Therapeutic
suppression
– Stewart treves
syndrome

5. WHO Classification (2013)
 Adipocytic
 lipoma, liposarcoma
 Fibroblastic
 myositic ossifican,
fibrosarcoma
 Fibrohistiocytic
 Tenosynovial giant cell tumor
 Smooth muscle
 leimyosarcoma
 Perivascular
 Myofibroma,
angioleiomyoma
• Skeletal muscle
– Rhabdomyoma,
rhambdomyosarcoma
• Vascular
– Harmangioma, kaposi
sarcoma
• Chondro osseous
– Soft tissue chondroma,
extraskeletal osteosarcoma
• Uncertain differentiation
– Fibromyxoma, synovial
sarcoma,

6. History
Parameter Benign Malignant Comments
Pain Rare Rare Uncommon in the
absence of nerve
or bone invasion.
Size <5cm >5cm
Location Superficial Deep to fascia 1/3 of STS are
superficial
Mobility Mobile Fixed
Consistency Soft Firm
Growth Stable Enlarging Synovial sarcoma
and clear cell
sarcoma grown
very slow
Intramuscular hemangioma presents with pain.
Benign peripheral nerve sheath tumors are tethered to the never so medial
lateral mobility present

7. Age wise
 In childhood
 Embryonal rhabdomyosarcoma is the most common
 Young adults
 Synovial sarcoma (<35 years)
 Old age
 Evenly distributed
 Liposarcoma
 Undifferentiated pleomorphic sarcoma

8. Physical examination
 Size of mass
 Depth
 Mobility
 Tenderness
 Transillumination
 Consistency
 Pulsation
 Neurological examination
 Regional lymph nodes

9.  Common features of malignant lump
 Lump>5cm
 Increasing in size
 Deep to fascia
 pain

10. Radiographic features
 Xray
 Soft tissue mineralization and bony involvement
 Myositis ossificans
 Hemangioma
 Synovial sarcoma
 Extraskeletal osteogenic sarcoma
 Chest xray

11. CT
 CT chest for staging
 Bony involvement
 Contraindication of MRI
 Pattern of mineralization

12. MRI
 Imaging modality of choice in the diagnosis and therapeutic
planning
 To determine size, site, anatomic relationship to
neurovascular bundle
 Preoperative radiation or chemotherapy responses and for
detecting local recurrence
 Most tumor demonstrate
 Dark signal on T1
 Bright signal on T2
 Donot follow this usual signaling pattern have a narrow
differential
 High T1 lipoma, low T1, low T2 fibromatosis

13. CT vs MRI – Cortical involvemet is seen better in CT

14. A typical MRI appearance of a soft tissue sarcoma in the arm

15. Intramuscular lipoma
T1 image - Fat suppression T2 image

16. Well differentiated liposarcoma
T1 Image Fat suppressed T2 image

17.  Helpful hints
 Any deep heterogeneous mass or mass >5cm regardless
of location is a soft tissue sarcoma unless proven
otherwise
 Cysts do not enhance centrally with gadolinium
 True lipomas are homogenous on all sequences
 Well differentiated to moderately differentiated
liposarcomas have areas of signal consistency with
normal fat but admixed with non-fatty signal

18. Biopsy
 Essential part of both
diagnosis and
management
 Core needle biopsy or
open biopsy
 Fine needle biopsy is not
sufficent to provide
information

19. Whoops
 Unplanned biopsy or
excision lead to
 Increased mortality
 Increased complex
surgery
 Increased local
recurrence
 Increased metastatic
disease
 Increased amputation
Vodanovich DA, Choong PF. Soft-tissue sarcomas. Indian journal of orthopaedics. 2018 Feb;52:35-44.

20.  Histology
 Histological grade is a major prognostic determinant
 Based upon
 Degree of mitosis
 Cellularity
 Presence of necrosis
 Differentiation
 Stromal content

21. Immunohistochemistry

22. American joint committee on
cancer (AJCC) staging
Stage Size Depth Grade Metastases
I Any Any Low No
II <5cm, any
depth or
>5cm
superficial
High No
III >5cm Deep High No
IV Any Any Any yes

24.  Surgical procedure based on
 Tumor location
 Tumor size
 Involvement of adjacent
anatomical structures
 Patient preference
 Response to neo-adjuvant
therapies

25.  Surgery
 Primary treatment
modality
 Aim is to excise the
whole tumor with tumor
negative margins

26. Prognostic Factors
 Increased risk of local recurrence
 Age>50 years
 Recurrent disease
 Positive surgical margins
 fibrosarcoma
 Increased risk of distant metastasis
 Size >5cms
 High grade
 Deep locations
 Recurrent disease
 Leiomyosarcoma

27. Metastatic potential of
histological subtypes
Low Intermediate High
Well differentiated
liposarcoma
Inflammatory myofibroblastic tumor Undifferentiated pleomorphic
sarcoma
Haemangipericytoma Dedifferentiated liposarcoma
Haemangioendothelioma Leiomyosarcoma
Solitary fibrous tumor Round cell liposarcoma
angiosarcoma
Synovial sarcoma
Rhabdomyosarcoma
Extraskeletal Ewings sarcoma
Epitheloid sarcoma
Alveolar soft part sarcoma
Malignant peripheral Nerve
Sheath tumor
Roland CL. Soft Tissue Tumors of the Extremity. Surgical Clinics. 2020 Jun 1;100(3):669-80.

28. Lymph Node spread
 An infrequent event
 Of total 10,731 2.1% had LN metastatis
 Poorer survival rate with LN spread
 Several variables
 Histologic subtypes
 Tumor grade
 Patient age
 Primary tumor size
1. Fong Y, Coit DG, Woodruff JM, Brennan MF. Lymph node metastasis from soft tissue sarcoma in adults. Analysis of data from a
prospective database of 1772 sarcoma patients. Annals of surgery. 1993 Jan;217(1):72.
2. Miccio JA, Jairam V, Gao S, Augustyn A, Oladeru OT, Onderdonk BE, Chowdhary M, Han D, Khan S, Friedlaender G, Lindskog DM.
Predictors of Lymph Node Involvement by Soft Tissue Sarcoma of the Trunk and Extremity: An Analysis of the National Cancer Database.
Cureus. 2019 Oct;11(10).

29.  Histological subtypes with increased Lymph node
metastases
 Rhabdomyosarcoma
 Synovial sarcoma
 Undifferentiated pleomorphic sarcoma
 Epitheloid sarcoma
 Angiosarcoma
 Clear cell sarcoma
 Neurofibrosarcoma
 Leiomyosarcoma
 fibrosarcoma
 Nodal disease has prognostic value
 Regional lymphadenectomy to improve survival rate
Miccio JA, Jairam V, Gao S, Augustyn A, Oladeru OT, Onderdonk BE, Chowdhary M, Han D, Khan S, Friedlaender G, Lindskog DM.
Predictors of Lymph Node Involvement by Soft Tissue Sarcoma of the Trunk and Extremity: An Analysis of the National Cancer Database.
Cureus. 2019 Oct;11(10).

30. Is resection enough?
 Half of patients with adequate local control of sarcoma
develop distant mets and die from disease
 Low cure rate
 Metastatic STS are rarely cured
 Systemic chemotherapy is the standard care in
pediatric sarcomas
 Chemotherapy in adult is controversial
 Whether or not there are small population of patients
truly benefit from adjuvant chemotherapy
Bajpai J, Susan D. Adjuvant chemotherapy in soft tissue sarcomas…Conflicts, consensus, and controversies. South Asian J Cancer.
2016;5(1):15-19. doi:10.4103/2278-330X.179687

31. Radiotherapy (RT)
 Small, low grade tumors <5 cms with 2 cm negative
margins may not require
 Should be added to
 If margin is close
 If extra muscular involvement is present
 If local recurrence would result neurovascular
involvement or amputation
 Improves local control but not survival
Tiong SS, Dickie C, Haas RL, O’Sullivan B. The role of radiotherapy in the management of localized soft tissue sarcomas. Cancer biology &
medicine. 2016 Sep;13(3):373.

32. Role of RT
 Downsizing prior to surgery
 Local control if surgery is impossible
 Due to medical comorbidities, surgery is
contraindicated
 Burden of metastatic disase
 Care must be taken to appropriately design fields to
exclude sensitive structures.
Tiong SS, Dickie C, Haas RL, O’Sullivan B. The role of radiotherapy in the management of localized soft tissue sarcomas. Cancer biology &
medicine. 2016 Sep;13(3):373.

33. Chemotherapy
 Cannot be used as a blanket therapy
 Can be used in size >5cm, high grade STS
 Chemo-sensitive STS
 Synovial sarcoma
 Leiomyosarcoma
 Angiosarcoma

34. Role of chemotherapy
 Downsizing
 Increase the rate of limb salvage surgery
 Acts as a surrogate marker of chemosensitivity of
disease
 Palliative care for metastatic STS
 Uncertain due to the limited randomized controlled trial

35. controversies
 Can radiotherapy be avoided?
 The appropriated time of radiotherapy in relation to
surgery
 The appropriate time of chemotherapy in relation to
surgery

36. Take home message
 Any lump >5cm should be treated as soft tissue
sarcoma unless proven otherwise
 Biopsy is the most to confirm the diagnosis
 Surgical resection is the standard treament modality
with negative surgical margins
 Adjuvant chemotherapy or radiotherapy can be given
for local control

37. Thank you.