Fig. 3

a Longitudinal section of the formalin-fixed bladder and uterus. On the left, the bladder mucosa shows a bulky and exophytic, withe-gray tumor (white arrow) that invades through the complete bladder wall, reaching the perivesical adipose tissue (yellow arrow). On the right, the uterine wall and endometrium are thickened (blue arrow), with no evidence of tumor invasion. In between both walls, the vesico-uterine pouch can be recognized. b Microphotograph of the bladder mucosa showing a well-differentiated squamous cell carcinoma with multiple keratinizing epithelial groups (pink nests) invading the subepithelial connective tissue. The mucosa has epithelial denudation, and the residual urothelial lining is hyperplastic (arrow). (Hematoxylin and eosin stain, original magnification × 40). c Image of one of the iliac lymph nodes with metastatic squamous cell carcinoma (hematoxylin and eosin stain, original magnification × 40)