Fibrosarcoma (fibroblastic sarcoma) is a
malignant tumor derived from fibrous connective tissue and characterized by immature
proliferating fibroblasts or undifferentiated
anaplastic spindle cells.
Pathology
The tumor may present different degrees of
differentiation: low grade (differentiated), intermediate malignancy and high malignancy (anaplastic). Depending on this differentiation, tumor cells may resemble mature fibroblasts (spindle-shaped), secreting
collagen, with rare mitoses. These cells are arranged in short fascicles which split and merge, giving the appearance of "fish bone". Poorly differentiated tumors consist in more atypical cells, pleomorphic, giant cells, multinucleated, numerous atypical mitoses and reduced collagen production. Presence of immature blood vessels (sarcomatous vessels lacking endothelial cells) favors the bloodstream metastasizing.
Fibrosarcoma in dogs and cats
Fibrosarcoma occurs most frequently in the mouth in dogs. The tumor is locally invasive, and recurs often following surgery.
Radiation therapy and
chemotherapy are also used in treatment. Fibrosarcoma is also a rare bone tumor in dogs.
In cats, fibrosarcoma occurs on the skin. It is also the most common vaccine-associated sarcoma.
See also
References
External links
