MSKS Pathology Lecture 5_Soft Tissue Tumors Flashcards
What is a lipoma? Where and when does it arise?
It is a benign tumor of fat cells. They tend to arise in the subcutis of the proximal extremities and trunk. They tend to form in middle adult hood. Like most -omas they tend to be well defined and mobile.
What is a Liposarcoma? Where and when does it arise?
It is a malignant tumor of fat cells. They tend to arise in the deep soft tissues of the proximal extremeties. They develop in people in their 50s and 60s. They are one of the most common sarcomas of adulthood.
What are the three types of liposarcomas?
1) Well-differentiated: This gives rise to amplification of gene for MDM2, which encodes an inhibitor of p53
2) Myxoid: This is a medium differentiated liposarcoma
3) Pleomorphic liposarcomas: these are not differentiated and have complex karyotypes
What is Nodular Fasciitis? How large are they and where do they arise?
It is a self-limited fibroblastic/myofibroblastic proliferation. It often occures in the upper extremities (deep dermis, subcutis, or muscle) in young adults. They are less than 5 cm in diameter
What is a Superficial Fibromatoses. Does it have a gender preference?
It is an infiltrative fibroblastic proliferation that can
cause local deformity, but has an innocuous clinical course. They more commonly effect men.
What are the three sub types of Superficial Fibromatoses
Palmar, Plantar, Penile
What is Deep Fibromatosis. Who is most affected?
large, infiltrative masses that frequently recur, but do not metastasize. They are more common in Women and arise in the late teens through the 30s
What causes Deep Fibromatosis
It is caused by a mutation in the Beta catenin pathway. this causes increased wnt signaling.
What is Rhabdomyosarcoma?
It is a malignant mesenchymal tumor with skeletal muscle. differentiation
What are the three types of rhabdomyosarcoma? who do they typically effect?
1) alveolar - effects kids under 20
2) embryonal - effects kids under 20
3) pleomorphic - typically seen in adults
What causes Alveolar rhabdomyosarcoma?
It is caused by the fussion of FOXO1 gene to PAX3 or PAX7 genes. The FOXO1 PAX3 fussion inhibits the mesenchymal cell from differenciating into a muscle cell
How do you treat Rhabdomyosarcomas?
With excision and chemo. They are very aggressive tumors.
What is a Leiomyoma
It is a begine tumor of smooth muscle cells. They often arise in the uteris and are the most common neoplasm in women (effecting up to 77%)
Where do Leiomyosarcoma typically occure and who do they effect?
They occure in the deep soft tissues, the retroperitinium, and they great vessicles (like the IVC) They effect women much more than men
