Fig. 15.34 Poorly differentiated (grade III) urothelial carcinoma
of bladder. The nuclei are very large and contain prominent nucleoli
(Papanicolaou x HP).
Fig. 15.36 Group of malignant cells from high-grade (III) urothelial
carcinoma of bladder. The nuclei display an irregular chromatin pattern and
contain nucleoli. The cytoplasm is focally eosinophilic (Papanicolaou x MP).
Fig. 15.35 Poorly differentiated (grade III) urothelial carcinoma of
bladder. Large pleomorphic tumor cells with irregular nuclei and a coarsely
granular chromatin pattern (Papanicolaou x LP).
in bladder exstrophy. Some of these patients have a history of
urinary tract lithiasis or infection, which may have caused glan-
dular metaplasia.41 The cytology is characterized by the presence
of clusters of columnar or cuboidal cells with large, hyperchro-
matic, irregular nuclei. The cytoplasm is usually vacuolated, with
large single vacuoles that push the nucleus toward the periphery.
The nuclei tend to be vesicular and contain large nucleoli and
dense chromatin strands. Signet ring cell (colloid) adenocarci-
nomas and clear cell (mesonephric) adenocarcinomas have also
been described but must be differentiated from clear cell-type
transitional cell carcinomas.38 Tumors arising from remnants of
the allantoic duct or urachus in the dome of the bladder are
other rare variants.
Key features of adenocarcinoma
• Clusters of columnar or cuboidal cells;
• Vacuolated cytoplasm;
• Large, irregular, and hyperchromatic nuclei; and
• Prominent nucleoli.
Fig. 15.37 Keratinizing neoplastic squamous cells in the urine of a patient with
squamous cell carcinoma of the urinary bladder (Papanicolaou x HP).
Adenocarcinom as of the Kidney
In late stages, these adenocarcinomas invade the renal pelvis
and then exfoliate into the urine. This is invariably preceded
by hematuria. The renal adenocarcinomas are often well differ-
entiated and usually of a clear cell type (Fig. 15.38). If tumor
cells are present in urine, they are large and have irregular cell
borders. The cytoplasm is abundant, well defined, and promi-
nently vacuolated and cells are usually clustered (Figs 15.39 and
15.40). Granular cell and oncocytic types may also be identified.
A cytologic diagnosis is occasionally made, but only in late or
advanced states. Cytology is not a useful diagnostic tool for this
condition. Renal collecting duct carcinoma is a relatively rare
variant of renal carcinoma but, because of its pelvic growth pat-
tern, appears to exfoliate readily. The cells found in urine are
large, with a high nucleocytoplasmic ratio, vesicular chromatin,
and prominent single or multiple eosinophilic nucleoli. Some
are seen in a gland-like arrangement.42 Wilms' tumor or neph-
roblastoma, one of the most common tumors of young chil-
dren, rarely exfoliates into urine, and cytology is not useful or