Fibrosarcoma cell. Coloured scanning electron micrograph of a fibrosarcoma (fibroblastic sarcoma) cell. The cell is covered in many microvilli. Fibrosarcoma is a malignant tumour derived from fibrous connective tissue of the bone and characterized by immature proliferating fibroblasts or undifferentiated anaplastic spindle cells. Magnification: x6000 when printed at 10 centimetres wide.