Fig. 1

Macroscopic and histological findings for a plasmacytoid urothelial carcinoma. a Gross examination of the cut surface of a nephrectomy specimen shows a whitish solid tumor with a partially myxoid change in the renal pelvis (arrows). b The tumor was mainly located in the renal pelvic mucosa and exhibited two distinct morphological components. c The tumor surface comprised a noninvasive urothelial carcinoma, including a high–grade papillary urothelial carcinoma and a carcinoma in situ. d Transitional findings between the urothelial carcinoma in situ and the invasive plasmacytoid urothelial carcinoma were recognized. e In the invasive area, the plasmacytoid tumor cells in the loose myxoid stroma were dyscohesive and lacked cell adhesions. f The plasmacytoid tumor cells had an eccentrically placed nucleus and an abundant amphophilic to eosinophilic cytoplasm. b-f. Hematoxylin and eosin–stained sections. Original magnification: b, Scanning view; c, × 40; d and e, × 200; f, × 400