Micropapillary urothelial carcinoma of the urinary bladder: a clinicopathological analysis of 24 cases.
OBJECTIVE
To stratify patients with micropapillary urothelial carcinoma of the urinary bladder based on the percentage of micropapillary component and to correlate tumor volume with other clinicopathological features.


METHODS
Cases of micropapillary urothelial carcinoma of the urinary bladder from 2002 to 2009 were identified. Only patients with available follow-up information were included in the analysis. Tumor volumes were stratified based on the percentage of micropapillary component (<50%, >50% and 100%).


RESULTS
Overall, 24 cases were analyzed. Mean patient age was 71 years (range 55-86 years), with a male to female ratio of 3:1. Six cases (6/24; 25%) were composed entirely of micropapillary component. A total of 12 cases (12/24; 50%) showed >50% micropapillary component. Six cases (6/24; 25%) showed <50% micropapillary component. A higher percentage of micropapillary urothelial carcinoma component was significantly associated with male sex, regional lymph node metastasis and pathological stage (P-values = 0.0005, 0.01 and 0.03, respectively). The percentage of the micropapillary component was, however, unrelated to patients' survival.


CONCLUSIONS
The present study confirms that micropapillary urothelial bladder carcinoma is typically aggressive and presents with advanced stage disease in most cases. A quantification of the micropapillary component is to be recommended. An accurate diagnosis of this entity in relatively small biopsies or transurethral resection of bladder tumor specimens is especially critical to define the best treatment plan.
Department of Pathology, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
Neil
N
Edgerton
S Joseph
SJ
Sirintrapun
Melissa
M
Munoz
Zhengjia
Z
Chen
Adeboye O
AO
Osunkoya
D000368:Aged; D000369:Aged, 80 and over; D002291:Carcinoma, Papillary / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D001743:Urinary Bladder / Q000473:pathology*; D001749:Urinary Bladder Neoplasms / Q000473:pathology*; D019459:Urothelium / Q000473:pathology*