Plasmacytoid urothelial carcinoma: a rapid autopsy case report with unique clinicopathologic and genomic profile

Abstract

Background Rapid (“warm”) autopsies of patients with advanced metastatic cancer provide important insight into the natural history, pathobiology and histomorphology of disease in treatment-resistant tumors. Plasmacytoid urothelial carcinoma (PUC) is a rare variant of urothelial carcinoma characterized by neoplastic cells morphologically resembling plasma cells. PUC is typically aggressive, high-stage at presentation, and associated with poor outcomes. Recurrence is common in PUC, with the majority of recurrences occurring in the peritoneum. Case presentation Here, we report rapid autopsy findings from a patient with recurrent PUC. The patient had persistent pain after cystoprostatectomy, although initial post-operative imaging showed no evidence of disease. Imaging obtained shortly before his death showed only subtle growth along vascular tissue planes; however, extensive disease was seen on autopsy. Plasmacytoid tumor cells formed sheets involving many serosal surfaces. Molecular interrogation confirmed a mutation in CDH1 exon 12 leading to early truncation of the CDH1 protein in the tumor cells. Conclusions The sheet-like growth pattern of PUC makes early phases of disease spread much more difficult to capture on cross-sectional imaging. Alternative forms of surveillance may be required for detection of recurrent PUC, and providers may need to treat based on symptoms and clinical suspicion.

Editorial Comment to Progressive plasmacytoid variant bladder cancer with retroperitoneal dissemination: An autopsy case report

“…Half of the PUC cases showed loss of E‐cadherin expression. The IHC analysis of pathological specimens can distinguish PUC from lobular breast and diffuse gastric carcinomas which share a similar morphologic appearance 2,3 . In this case, the authors revealed higher HER2 expression within the autopsy PUC specimen.…”

“…Therefore, urologists should be cognizant of the inherent limitations in diagnosing PUC relapse. Patients may require treatment based on symptoms and clinical suspicion 2 . Circulating tumor cells (CTCs) are indicators of recurrence and prognosis for several types of cancers, and can provide information about tumor biology.…”

“…Autopsies can establish the extent of clinical disease and help clinicians to understand the clinical and pathological aspects of that disease 2 . During IHC analysis, almost all PUC cases showed expression of urothelial markers (GATA‐3) and plasma cell markers (CD138).…”

Progressive plasmacytoid variant bladder cancer with retroperitoneal dissemination: An autopsy case report

“…[1][2][3][4] The current case is the second autopsy report of PUC. 6 Moreover, to the best of our knowledge, this study is the first to assess the CTCs.…”

Clinically undetected plasmacytoid urothelial carcinoma of the urinary bladder with non-mass-forming metastases in multiple organs: an autopsy case

“…PUC may pose a significant diagnostic problem, particularly when it occurs in its exclusively pure or predominant pattern in a limited biopsy, cytology, or transurethral resection specimen. Moreover, reflecting an infiltration pattern arranged as diffuse, thick sheets, cords, or nests of small discohesive tumor cells without forming a focal mass [5], it is challenging to detect PUC via imaging procedures [6,7]. Initial manifestations of PUC may include distant metas-tasis or peritoneal dissemination [8].…”