Exam 5 soft tissue tumors Flashcards
T/F: Lipoma is benign
True
T/F: Liposarcomas are malignant
true
How to soft tissue tumors develop?
develop due to mutations in mesenchymal stem cells
What are the most common mutations leading to soft tissue tumors?
translocations leading to a fusion gene which usually results in chimeric transcription protein
what causes Kaposi’s Sarcoma?
Human Herpesvirus-8
What is the histological grade of a soft tissue tumor based on?
tumor differentiation score, mitotic count, amount of tumor necrosis
What is the largest risk factor of metastasis of a soft tissue tumor?
Size (20cm = 80% chance of metastasis)
What are the most common types of soft tissue tumors in adults?
Lipomas
Describe a conventional lipoma
most common type, mature fat only
Describe an angiolipoma
mature fat with small vessel proliferation
Describe spindle cell lipoma/pleomorphic lipoma
Mature fat plus spindle cells/pleomorphic cells
Where do most soft tissue lipomas occur? What’s there treatment?
Usually superficial location and are well circumscribed and encapsulated; treat with surgical excision
What age group do liposarcomas occur in?
middle to older age adults
What are the morphological variants of lip sarcomas?
Well differentiated, Myxoid/round cell, Pleomorphic
What are the two types of fibrous tumors and tumor-like lesions?
Nodular fasciitis, Myositis ossificans
What can palmar fibrzomatosis lead to?
Dupuytren’s contracture
What are the most common mutations in deep-seated fibrzomatosis?
somatic beta-catenin or adenomatous polyposis coli (APC gene)
What is the most common soft-tissue sarcoma of childhood/adolescence?
Rhabdomyosarcoma (skeletal muscle differentiation)
What factors influence the prognosis of rhabdomyosarcoma?
size, patient age, location
Where do tumors of smooth muscle occur?
Most commonly on uterus; typically benign
What is the most common neurofibromatosis linked with malignant peripheral nerve sheath tumors?
NF-1
Where do synovial sarcomas typically occur?
para-articular regions of the extremities in adolescents and young adults
