The neoplastic spindle cells of osteosarcoma are seen to be making pink osteoid here.

Results In HE staining, the tumor cell was spindle, irregular and disorder arrangement, mixing with lymph cell and collagen fibers.

The schwannoma is seen microscopically to be composed of spindle cells (like most neoplasms of mesenchymal origin), but the cells are fairly uniform and there is plenty of pink cytoplasm.