Figure 1

H&E morphology. (a) Neoplastic tumor nests of invasive micropapillary carcinoma free-floating in cleft-like spaces (original magnification × 100). (b) Multiple nests and papillae in single retraction spaces characteristic of invasive micropapillary carcinoma (original magnification × 400). (c) Typical invasive urothelial carcinoma frequently demonstrates retraction surrounding tumor nests (original magnification × 200). (d) Single tumor nests/aggregates within a single space and larger confluent nests are typical (original magnification × 400).