Image Description
The tumor is composed of fibroblastic and histiocytic cells arranged in sheets or intersecting fascicles. Inflammatory cells consisting of lymphocytes, plasma cells and foamy histiocyotes are also seen in this image. The stroma contains delicate collagen fibers in between cells. Mitotic activity is not increased. Cytologic atypia is absent; however, some cases show "degenerative" atypia.