Identification of a diagnostic marker for DFTD. (A to D) Hematoxylin and eosin (H&E) and (E to H) PRX antibody stains used for DFTD tumor histology. Arrowheads, DFTD tissue; arrows, peripheral nerve bundles (containing Schwann cells). Magnification, 4× (A and E; scale bar, 200 μm); 20× (B and F; scale bar, 50 μm); and 100× (C and G) peripheral nerve bundle (scale bar, 20 μm) and (D and H) DFTD tumor (scale bar, 20 μm). Boxed areas indicate approximate locations of areas magnified in lower panels.