Soft Tissue Sarcomas Flashcards
What is the cell origin of a STS?
Mesenchymal
Where do STS most commonly develop in the dog?
Subcutaneous
What are biological factors of a STS:
A) Arise from?
B) Appear as?
C) Infiltrate..
D) After conervative excision
E) Mets route
F) Chemo/radio response..
A) Any anatomical site in the body;
B) The propensity to appear as pseudoencapsulated tumours with poorly defined histological margins;
C) through fascial planes;
D) Common local recurrence
E) haematogenous route;
F)A poor response in cases where gross tumour is present.
What mesenchymal tumours aren’t classified as a STS? (they can usually be reliably identified on light microscopy (especially when anatomical location is known) and because their individual biological behaviour has a more defined character) (5)
- Haemangiosarcoma
- Synovial cell sarcoma
- Gastrointestinal stromal tumours (GISTs)
- Fibrosarcoma involving the oral cavity
- Peripheral nerve sheath tumours arising from the brachial or lumbosacral plexus.
Which of the following is the most common site for metastasis of soft tissue sarcomas?
Lung
Met rate of STS?
Mild - moderate
What genes are associated with STS in canines?
P53 mutations and MDM2 gene amplification
Although little is known, what are some association of STS causes in cats and dogs?(6)
- Gene
- Chronic trauma
- FB
- Vacc
- Parasite
- Radiation
Sex and breed for STS?
no associations made
If STS if found younger, what is the nature of the STS?
More biologically active.
Median age for STS?
10-11yr
What is the normal growth rate for a STS?
Slow
Where are STS most commonly found? (3)
Head
Limbs
Trunk (incl tail)
Why are only 50% of STS diagnosed on FNA?
limited exfoliative character
What is the prognositc factor for STS?
Histo grading
What gauge percutaenous needle core biopsy for STS?
12-14fg
How can a biopsy instrument be placed into STS? (2)
- palp
- U/S guided
How many samples should you obtain as a minimum if taking a Tru-cut core biopsy?
6
What is the main risk for biopsy?
Seeding along biopsy tract
STS: OTher adjuvant diagnostic evaluations? (6)
-Routine blood work
-Radiographs of the local tumour site for possible underlying bone infiltration
-Ultrasound of the tumour
-Radiographs of the chest for possible metastatic spread
-FNA of the regional lymph node
-CT or MRI imaging techniques.
One retrospective study with 350 patients found that more than A) % of the STS resections performed in primary care practice were “B),” with the operating surgeon having no knowledge of the identity, behaviour or C) potential of the mass they were removing. The higher proportion of low‐grade (and thus less D)) forms of STS encountered in primary care practice probably compensates for this lack of E) and enables patient outcomes to remain reasonable
A) 80%
B) Unplanned
C) Invasive
D) Aggressive
E) Planning
There are currently no A) that can reliably predict the precise surgical margins required for a particular STS, but there are several validated and suspected prognostic factors that have been reported (Dennis et al. 2011). These include the B) characteristics of the tumour (i.e., grade, histologic type, mitotic count etc.), C) characteristics (i.e., size, location, palpable features), as well as other clinical factors such as patient D) and E) Following removal of the tumour, the completeness of the F) is also an important prognostic criterion to evaluate in the context of an overall treatment plan.
A) Diagnostic test
B) Histological
C) Physical
D) Age
E) Co-morbidities
F) Excision margins
What do the grading scores of STS relate to? (4)
histological differentiation,
number of mitoses per high power field,
tumour necrosis
histological grade.
Define good differentiation score 1
- Sarcomas most closely resembling normal adult mesenchymal tissue, by type (e.g., well‐differentiated perivascular wall or peripheral nerve sheath tumours, well‐differentiated fibrosarcomas, or well‐differentiated liposarcomas).
Define moderate histological differentiation score 2
Sarcomas for which histologic type can be determined, although differentiation is poor (e.g. poorly differentiated liposarcoma, fibrosarcoma, poorly differentiated perivascular wall tumour or peripheral nerve sheath tumour).
Define histological differentiation score 3
Undifferentiated sarcomas, sarcomas of unknown type.