S-100 protein in granular cell tumors. (Granular cell myoblastomas)

Abstract
Outside the central nervous system S-100 is found only in Schwann cells and satellite cells of ganglia. It has also been demonstrated in Schwannomas and neurofibromas but is absent from soft tissue tumors of non-neural origin. S-100 protein was looked for in granular cell myoblastomas using an immuno-histochemical technique in an attempt to further elucidate the histogenesis of these tumors. All tumor cells in the ten tumors studied were intensely stained with antiserum to S-100 including one with some malignant features. These results support the idea that granular cell myoblastomas arise from Schwann cells.