Plasmacytoid urothelial carcinoma (PUC): Imaging features with histopathological correlation.
BACKGROUND
Plasmacytoid urothelial carcinoma (PUC) is a high-grade variant of conventional urothelial cell carcinoma. This study is the first to describe the imaging findings of PUC, which are previously unreported, using clinical and histopathological correlation.


METHODS
With internal review board approval, we identified 22 consecutive patients with PUC from 2007-2014. Clinical parameters, including age, gender, therapy, surgical margins, and long-term outcome, were recorded. Baseline imaging was reviewed by an abdominal radiologist who evaluated for tumour detectability/location/morphology, local staging, and presence/location of metastases. Pelvic peritoneal spread of tumour (defined as >5mm thick soft tissue spreading along fascial planes) was also evaluated. Followup imaging was reviewed for presence of local recurrence or metastases.


RESULTS
Median age at presentation was 74 years (range 51-86), with only three female patients. Imaging features of the primary tumour in this study were not unique for PUC. Muscle-invasive disease was present on pathology in 19/22 (86%) of tumours, with distant metastases in 2/22 (9%) at baseline imaging. Pelvic peritoneal spread of tumour was radiologically present in 4/20 (20%) at baseline. During followup, recurrent/residual tumour was documented in 16/22 (73%) patients and 7/16 (44%) patients eventually developed distant metastases. Median time to disease recurrence in patients who underwent curative surgery was three months (range 0-19).


CONCLUSIONS
PUC is an aggressive variant of urothelial carcinoma with poor prognosis. Pelvic peritoneal spread of tumour as thick sheets extending along fascial planes may represent a characteristic imaging finding of locally advanced PUC.
Department of Medical Imaging; The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
Andrew D
AD
Chung
Department of Medical Imaging; The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
Nicola
N
Schieda
Department of Anatomical Pathology; The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
Trevor A
TA
Flood
Department of Surgery, Division of Urology; The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
Ilias
I
Cagiannos
Department of Anatomical Pathology; The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
Kien T
KT
Mai
Department of Radiation Oncology; The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
Shawn
S
Malone
Department of Surgery, Division of Urology; The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
Christopher
C
Morash
Department of Anatomical Pathology; The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
Shaheed W
SW
Hakim
Department of Surgery, Division of Urology; The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
Rodney H
RH
Breau