Renal pelvic plasmacytoid subtype urothelial carcinoma accompanied with solitary mammary metastasis

Abstract

A 72-year-old female was referred to our institution for further evaluation of right renal tumor detected during work-up for macroscopic hematuria in other hospital. CT urography performed at our institution suggested renal pelvic tumor. Voiding cytology was atypical. CT also revealed a small mass in the right mammary gland. Percutaneous needle biopsies were performed on the right mammary gland and renal mass, leading to a pathological diagnosis of UC with plasmacytoid subtype, suggesting metastasis from the renal pelvic UC to the mammary gland. She had a favorable response to four cycles of dose-dense MVAC therapy; therefore, we performed nephroureterectomy. One month after nephroureterectomy, new intraperitoneal metastatic lesions were observed and pembrolizumab therapy was started. After seven doses of pembrolizumab, CT revealed a marked size reduction of intraperitoneal metastases and the mammary metastasis remained small.

Keywords: Plasmacytoid subtype; Renal pelvic cancer; Solitary mammary metastasis; Urothelial carcinoma.

Fig. 1

CT findings A Contrast-enhanced CT showing renal pelvic tumor extensively invading the renal parenchyma (arrowhead), and plain CT revealing solitary mammary small tumor (arrow). B Plain CT showing the mammary tumor and renal pelvic tumor markedly growing during the 3-month period. C Contrast-enhanced CT showing the mammary tumor markedly decreasing in size and renal pelvic tumor slightly decreasing in size after chemotherapy. D Contrast-enhanced CT showing the mammary tumor maintaining shrinkage and new onset of multiple intraperitoneal metastatic lesions (circles) one month after surgery. E Contrast-enhanced CT showing the mammary tumor maintaining shrinkage and the multiple intraperitoneal metastatic lesions disappearing after seven doses of pembrolizumab therapy

Fig. 2

Pathological findings (A ×40, B–F ×200) Hematoxylin and eosin staining of mammary tumor revealed discohesive tumor cells with eccentrically placed nuclei (arrowhead) and abundant eosinophilic cytoplasm (A, B). Immunohistostaining was negative for ER, PgR, and HER2 (not shown) but positive for GATA3 (C). E-cadherin staining showed distinct positive (*) and negative (**) areas (D). Additional immunohistostaining was positive for p63 (E). An obvious plasmacytoid subtype component was not observed in the nephroureterectomy UC specimens (F)