15
Urinary Tract
Fig. 15.41
umor cells with salt-and-pepper chromatin in
catheterized urine of a patient with small-cell carcinoma of bladder
(Papanicolaou x MP).
Fig. 15.43 Urothelial carcinoma of the urethra. The tumor cells have
hyperchromatic nuclei (Papanicolaou x MP).
Fig. 15.42 Histology of small-cell carcinoma of bladder, same patient
as Fig. 15.41 (H&E x MP).
urethra, and periodic, regular follow-up examinations are there-
fore indicated. The specimens are best collected by saline lavage
of the urethra and collection of the efflux in an equal amount
of 50% alcohol. Many of the cases detected are transitional cell
carcinomas in situ. The cytologic morphology is similar to that
of bladder tumors. Invasive carcinoma may also be found.
Condylomata acuminata and rarely flat condylomata occur
in the urethra, usually near the meatus. The cytologic findings
correspond to those of condylomata at other sites.
Urethral caruncles are lesions of elderly women. They are
also located near the meatus and are polypoid. Cleft-like spaces
are lined by hyperplastic urothelial cells, and the stroma is char-
acterized by chronic inflammatory changes. The epithelium may
be hyperplastic, but it is rarely the source of an erroneous false-
positive diagnosis.
Upper Collecting System of the Urinary Tract
Urothelial tumors of the upper urinary tract histologically resemble
those of the urinary bladder. Tumors of the pelvis are more com-
mon than those of the ureter. They are often associated with blad-
der tumors, and many are multifocal or extensive and invasive.46
Tumors of the renal pelvis may infiltrate deeply into the kidney and
form large masses that grossly resemble renal adenocarcinoma.
For a number of years, the standard diagnostic regimen for
evaluating intrinsic upper urinary tract urothelial lesions con-
sisted of cystoscopy, intravenous or retrograde pyelography, and
upper tract urine cytologic studies. The addition of the uretero-
pyeloscope to the diagnosis of upper tract disorders was widely
heralded as a major breakthrough, with improved detection of
renal pelvic and ureteral tumors noted by several studies.15,47,48
This instrument with either rigid or flexible design enables direct
visualization of lesions throughout the upper urinary tract and
allows assessment of the stage, size, location, and multicentricity
of tumors. Grossly visible lesions can be biopsied, and thera-
peutic procedures such as endoscopic resection and fulguration
of urothelial tumors can be performed.49 By far the greatest suc-
cess in diagnosing tumors of the upper urinary tract has been
achieved with forceps or basket technique.50
Urinary cytology is usually diagnostic in high-grade tumors
which present nuclei with clear-cut criteria of malignancy. In well-
differentiated papillary urothelial carcinomas, the urine samples
may be hypercellular, but there are no significant cytologic devia-
tions, and a definite diagnosis is possible when cell blocks are
available (Figs 15.44 to 15.51). At our institution, multiple sam-
ples are obtained by urine aspiration, saline lavage, and biopsy of
visible tumor, by a basket or cup forceps, during ureteroscopy. All
samples are processed in the cytology laboratory where cytospins
and cell blocks are prepared. Since practicing this handling tech-
nique, our ability to diagnose and grade upper tract neoplasm has
improved markedly: 91% accuracy was obtained using the lavage
cytology, and 95% combining smear and cell block of the biopsy
specimen15 (Table 15.4). In a study comparing ureteroscopic
biopsies and cytological specimens with open surgical specimens
of urothelial tumors, accurate information regarding grade and
stage was obtained.49 Grading has become the most predictive
value in defining therapeutic approach. In addition to morpho-
logic parameters some biologic markers may be used to increase
the accuracy of grading such as DNA analysis, cytokeratin 20
expression, and P53 protein expression.51-54 Endoscopic treatment
of upper urinary tract carcinomas is a reasonable method for treat-
ing selected patients with low-grade tumors, with complete endo-
scopic follow-up at regular intervals to rule out recurrences.55
Caution and conservatism in interpretation of cytologic
samples are necessary because catheterized specimens from the
upper urinary tract contain large numbers of superficial cells and
often show a degree of atypia not seen in voided or catheterized
427
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