Solitary Fibrous Tumor : Histology
Histologic Features: Solitary fibrous tumors are composed of round or spindle cells arranged haphazardly (patternless pattern) or in short, intersecting fascicles around a rich vascular network. Some cases show vague storiform pattern (as shown in this image). The tumor cells lack cytologic atypia and have moderate amount of eosinophilic cytoplasm with indistinct borders. Mitotic activity is not increased.