Fig. 1

a Tumor in the urethra with representative images of hematoxylin and eosin (HE) (b) and β-catenin (c) staining. HE staining showed papillary architecture with morphological features of ductal adenocarcinoma including tall, columnar, pseudostratified epithelium. Focal nuclear β-catenin staining is seen (arrows in c). Bars indicate 100 μm