Fibrosarcoma

Fibrosarcoma

Fibrosarcoma (fibroblastic sarcoma) is a malignant connective (soft) tissue tumor which originates from fibroblasts. The tumor may present different degrees of differentiation : low grade (differentiated), intermediate malignancy and high malignancy (anaplastic). The degree of differentiation is set according with: resemblance of tumor cell with mature fibroblast (spindle-shaped), amount of collagen secretion and mitotic rate. Tumor 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. (Hematoxylin-eosin, ob. X20)

Last updated : 01/30/2009