Immunohistochemistry shows the cells are β-catenin, vimentin, Ki-67, SMA, CD68, and CD34 positive, which can assist with the diagnosis.[16] The differential diagnosis of FAP associated with DTs includes metastatic tumors, lymphomas, tumors of mesenchymal origin, fibrosarcoma, and neurofibroma. The gene discussed is SMN1; the disease is fibrosarcoma.