Sarcoma Flashcards
How common are adult sarcomas (percentage of malignancies)
1%
15% of childhood malignancies
What are the most common sarcomas in young adults
Synovial, Ewing, alveolar rhabdomyosarcoma
What are the most common sarcomas in older adults
Liposarcoma, leiomyosarcoma, undifferentiated pleomorphic sarcoma, fibrosarcoma
What is the median age for adult sarcomas
50-60
What sarcomas are associated with NF1?
Malignant peripheral nerve sheath tumours
Rhamdomyosarcoma
What sarcomas are associated with Li-Fraumeni syndrome?
Rhabdomyosarcoma
Which sarcomas are most commonly associated with previous radiation therapy
Angiosarcoma, undifferentiated pleomorphic, fibrosarcoma
What general type of tissue do sarcomas arise from
Mesenchymal
How is T stage defined for extremity soft tissue sarcomas
T1 = 5.0
T2 5.1-10.0
T3 10.1-15
T4 15.1+
N1= any node involvement
How is soft tissue extremity sarcoma staged
I: Tany N0M0 grade 1
II: T1 grade 2-3
III: T2-4 grade 2-3
IV: any N or M involvement
What are some examples of less aggressive and aggressive fibromatosis
Dupuytrens (benign)
Desmond tumours: frequently recur, but do not metastasize.
Which type of sarcoma arises from adipose tissue, what are the main subtypes
Liposarcoma
-well differentiated (amplification of region of chromosome 12q encoding MDM2 and CDK4)
-myxoid (t12;16 translocation)
-pleomorphic (complex karyotype/genetic instability)
What type of sarcoma is associated with skeletal muscle. What are the most common subtypes
Rhabdomyosarcoma
-note they arise in areas without skeletal muscle as they arise from stem cells rather than differentiated myocytes
-Alveolar (most common in childhood, specific common translocation pax:FOX01)
-embryonal (childhood); includes spindle cell/sclerosing. Negative for pax:fox01
-pleomorphic/undifferentiated
What type of sarcoma is associated with smooth muscle and where are they most commonly found
Leiomyosarcoma
Found in extremities and retroperitoneum.
What type of sarcoma is associated with cartilage
Chondrosarcoma
What type of sarcoma is associated with blood vessels. What is the benign condition
Angiosarcoma
Benign:haemangioma
What are the microscopic features of undifferentiated pleomorphic sarcoma
Pleomorphic, bizarre cells
MANFICS
Mitosis
Atypia
Necrosis
Foamy cytoplasm
Inflamed collagenous cytoplasm
Which sarcomas are more likely to metastasis to lymph nodes
CARE
Clear cell sarcoma
Angiosarcoma
Rhabdomyosarcoma
Epithelioid sarcoma
What is the most radiosensitive type of adult soft tissue sarcoma
Myxoid liposarcoma
What IHC markers are general for all muscle types
Desmin
MSA (muscle specific actin)
What is one IHC specific to smooth muscle, and one specific to skeletal muscle
SMA (smooth muscle actin): smooth muscle
MyoD: skeletal/striated muscle. This is a nuclear marker
What are the microscopic features of myxoid liposarcoma
Uniform round to oval shaped primitive non-lipogenic cells
Chicken wire vasculature
Abundant myxoid matrix
Multivacuolar and univacuolar lipoblasts (sometimes with appearance of small signet ring cells)
What are key genetic/molecular abnormalities associated with well differentiated liposarcoma
12q amplification, which results in amplification of CDK4 (cell cycle progression) and MDM2 (p53 breakdown)
FISH for MDM2 amplification
p16 positivity is a highly sensitive, but non-specific surrogate for CDK4 amplification (due to negative feedback loop)
What sarcomas are most associated with distant metastasis
Leiomyosarcoma
Dedifferentiated liposarcoma and myxoid liposarcoma
What are the two histological patterns of synovial sarcoma
Monophonic: spindle cells only
Biphasic: spindle cells and epithelial cells
What are the components of grading of soft tissue sarcomas
1- differentiation
2- mitotic rate
3- necrosis
What is the relevance of IHC for myxoid liposarcoma
Not usually required.
Should be S100 positive
t(12:16) and t(12:22)
How is leiomyosarcoma defined
Smooth muscle tumour with:
-atypia
AND
-mitotic activity OR necrosis OR size >10cm
Otherwise would be a leiomyoma
What are the epidemiological patterns of leiomyosarcoma
Median age 60-69
Usually female
A/w EBV in immune compromised patients
Third most common retroperitoneum sarcoma
What is the microscopic appearance of leiomyosarcoma
Spindle cells in intersecting fascicular arrangements
Elongated cigarette shaped nuclei
What is the typical IHC profile of leiomyosarcoma
Positive: SMA, vimentin, desmin, CD34, S100
Negative: CD117
What is the characteristic architecture of fibrosarcoma
Herringbone
What is the main value of grading soft tissue sarcomas, and what are the three components of grading
Prognosticates for OS and development of metastasis. Does not predict local recurrence risk
Composed of:
-differentiation
-mitotic count
-degree of necrosis
Which sarcomas are high grade by definition
Ewings
Rhabdomyosarcoma
Epithelioid sarcoma
Clear cell sarcoma
Alveolar soft part sarcoma
How is myxoid liposarcoma graded
Based on the percentage round cell component
>5% = high grade
How are bone sarcomas graded
Based on the histological subtypes
What constitutes a good response to neoadjuvant chemotherapy in oesteosarcoma/ Ewings sarcoma
<10% viable tumour
How are margins defined in sarcoma
Radical: margin through normal tissue, extracompartmental
Wide: margin through normal tissue, intracompartmental
Marginal: margin within reactive zone, but extracapsular
Intralesional: within lesion
The aim is to achieve a “wide margin”
Numerically aim for margin of 1-2cm
What is the role of radiation therapy for bone sarcomas
Ewings (but first line is chemo and surgery)
Inoperable osteosarcoma and chondrosarcoma
What are the IHC and microscopic differences between kaposi sarcoma and angiosarcoma
Both: Infiltrative vascular channels. CD34, CD31 positive
Kaposi: HHV8+. Mitosis, but minimal nuclear atypia or pleomorphism. Spindled cells. Extravasation of erythrocytes, hemosiderin
Angiosarcoma: HHV8 negative. Marked nuclear atypia. Usually in sun damaged or radiation exposed skin
