Soft Tissue Tumors Flashcards
where are the dermis and connective tissue derived from?
mesoderm
where is the muscular system (smooth and skeletal) derived from?
mesoderm
What are mesnechymal (soft tissue) tumor? How are they calssified?
- nonepithelial extraskeletal tumors (excluding reticuloendothelial system, glia, and supporting tissue of parenchymal organs)
- classified according to the tissue they recapitulate (muscle, fat, fibrous tissue, vessel or nerves) the tissue they are trying to be
- benign soft tissues=oma
- malignant soft tissue tumors=sarcomas
what percentage of cancers are sarcomas?
1%
benign outnumbers sarcomas by 100:1
How do soft tissue tumors occur?
- a majority of soft tissue tumors occur sporadically, but an important minority are associated with genetic syndromes
- ex: Neurofibroms (NF1-malignant peripheral nerve sheath tumor), Garder Syndrome (fibromatosis) APC, Li Fraumen syndrome (soft tissue sarcomas) p53, hereditary hemorrhagic telangiectasia- multiple genes
- cause of most is unknown
How does the incidence of sarcomas relate to age?
incidence increases with age. 15% arise in children
- Rhabdomyosarcomas in childhood
- synovial sarcoma in young adulthood
- liposarcoma and pleomorphic or undifferentiated sarcomas in later adutl life
Where do sarcomas occur?
any location! 60% in extremities, with 40% being in lower extremities (especially thighs)
Accurate histologic classification contributes significantly to establishing the prognosis of a sarcoma. what are 2 important diagnostic features?
- cell morphology and architectural arrangement
- ancilalary techniques help esp when the diagnostic features are hard to distinguish for example in a poorly differentiated tumor
- Immunohistochemistry
- electron microscopy
- cytogenetics
- molecular genetics
What predicts the behavior of a soft tissue sarcoma? What are a few other afctors that distinguish prognosis?
Grade!
I-III (low, medium, high)
- degree of differentiation/pleomorphism
- average nuber of mitoses per high-power field
- extent of necrosis (presumably a reflection of rate of growth)
size and depth and stage of tumor are also important in deciding prognosis (superficial is better prognosis than deep lesions)
How do we usually treat sarcomas?
soft-tissue sarcomas are usually treated with wide surgical excision (frequently limb sparring). radiation and chemotherapy are used for large and/or high grade tumors
WHere are lipoma, hibernoma, liposarcomas located?
adipose tissue
where are neurofibroma, schwannoma, perineuriroma, malignant peripheral nerve sheath tumor (MPNST) located
nerve
where are leiomyoma, leiosarcoma and rhabdomyoma, rhabdosarcoma located?
muscle lei=smooth, rhabdo=skeletal
where are hemangioma, hemangioendothelioma, angiosarcoma located?
blood vessle
WHat is the most common soft tumor of adulthood?
lipoma
tell me about lipomas? what is their growht like? how to you treat them?
- most common soft tissue tumor os adulthood
- benign solitary lesion (multiple lipomas suggest presence of rare hereditary syndrome)
- most are mobile, slowly emerging, painless masses ( angiolipomas can manifest wiht local pain)
- complete excision is curative
How are lipomas subclassed? what are typical lipomas like? what do you see on histological exam? What are the typical abberations?
- subclassified according to particular morphologic features (angiolipoma, spindle, cell lipoma)
- conventional lipomas are soft, yello, well-encapsulated masses
- on hitological exam they consist of mature white fat cells with no pleomorphism
- 12q14-q15
How common are liposarcomas? where do they occur? what are they like morphologically?
- one of most common sarcomas
- deep soft tissues of proximal extremities and retroperitoneum
- may develop int large tumors
- well-diffeentiated, myxoid/round cell, and pleomorphic histologica variant
what geneticall yspeaking usually causes a myxoid/round LPS
t(12;16) (q13;p11) forms a FUS-CHOP fusion gene
What are fibrosarcomas? who gets them? where do they occur? How do they behaive?
- malignant tumors composed of fibroblast
- mostly adults
- deep tissues of the thigh, knee, and retroperitoneum
- aggressive tumors
- recur in >50% of cases
- metastasize in ?25%
What are Leimyosarcomas? Who typically gets them? where do they occur? prognosis?
malignant smooth muscle tumors
- 10-20% of soft tissue sarcomas, occur in adults and in females over males
- occur in the skin and deep soft tissues of the extremities and retroperitoneum
- when superficial and small they have a good prognosis, but when in retroperitoneum and large the can’t easily be excised and local extension and metastatic spread occur
WHat is a botryoid?
an embryonal RMS often in infant grils with protruberant vaginal lesions; also GU and head and neck
polypoid, gelatinous mass wiht a “bunch of graps” appearance
often has “cambium layer” of tumor cells underlying the native epithelium
What percentage of RMS are alveolar? what age is alveolar RMS common? where do they occur? What is the common cytogenetics that defines it?
- 31% of RMS
- More frequent between age 10 and 25
- occurs in
- deep soft tissues of the extremities
- leff frequently in head and neck, perineum, pelvis, retroperineum
- ARMS has pathognomic translocations
- t(2;13)/ FOXO1 (FKHR)
- t(1;13(/PAX7-FOXO1 (FKHR)
**named bc looks like alveoli histologically
synovial sarcoma incidence? location? what does ti look like histologically? translocation?
5-10% of all soft sarcomas, yong adults usualyl male
over 80% occur in deep soft tissue of extremities, especially around the knee
histologically biphasic or monophasic
cahracterized by cytogenetic change: t(x;18) (p11;q11) with SYT-SSX1 or SYT-SSX2
is this tissue monophasic or biphasic?
monophasic
is this tissue monophasic or biphasic?
biphasic
