The nested variant of urothelial carcinoma: a rare but important bladder neoplasm with aggressive behavior. Three case reports and a review of the literature.
OBJECTIVE
To describe our experience with the nested variant of urothelial carcinoma (UC-NV) of the bladder, by characterization of the clinical picture and the prognostic implications of this rare form of bladder neoplasm.


METHODS
Three cases of UC-NV of the bladder treated in our institutions were revised and data compared with previously published case-reports.


RESULTS
Three patients presented with advanced muscle-invasive UC-NV, of which two had lymph node metastasis at cystoprostatectomy. The histopathology in the latter two cases showed the same picture in the lymph node metastasis as in the primary tumor with nests of tumor cells with mild-moderate atypia. In all three cases the tumor involved a ureteric orifice or the bladder neck.


CONCLUSIONS
UC-NV is a rare but important histopathologic entity. It has a poor prognosis. At early stage, tumors might be difficult to differentiate from benign conditions and awareness of the condition is of outermost importance.
Liedberg
Fredrik
F
Department of Urology, Lund University Hospital, SE-221 85, Lund, Sweden. fredrik.lieberg@skane.se
Chebil
Gunilla
G
Davidsson
Thomas
T
Gadaleanu
Virgil
V
Grabe
Magnus
M
Mansson
Wiking
W
D000368:Aged; D002295:Carcinoma, Transitional Cell / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology*; D003937:Diagnosis, Differential; D018450:Disease Progression; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009130:Muscle, Smooth / Q000473:pathology; D009361:Neoplasm Invasiveness; D011379:Prognosis; D017678:Sex Distribution; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology*; D019459:Urothelium / Q000473:pathology