Urothelial carcinoma

Papillary carcinoma Grade I - voided urine

• The background is clean
• Cellularity, consisting almost entirely of single cells, is increased
• Tumour cells are similar to normal urothelial cells
• Some loose clusters of urothelial cells
• The chromatin is vesicular
• Nucleoli usually absent

G1 papillary carcinoma is difficult to diagnose cytologically because of the vesicular pattern of the chromatin and the non prominent nucleoli. These features are similar to normal or inflammatory urine.

Papillary carcinoma Grade I - bladder washings

• Nuclei with small border indentation
• Highly visible nuclear membrane
• Some distinct chromatin clumping
• Many cell groups with compact irregular shape or ”finger” shape
• Small, compact cells with green cytoplasm
• Absent or only a few dissociated tumour cells

Grade II urothelial carcinoma - voided urine

• Higher cellularity with presence of single cells and groups
• Nuclei are larger
• Cell groups show nuclear crowding
• Nuclei borders can be a little irregular (angulated)
• The chromatin is coarse
• The background is clean

Grade II urothelial carcinoma – bladder washings

• Irregular nuclei but without pronounced angular nuclear outlines 
• Coarse chromatin drawing
• Well marked nuclear membrane
• Spots of light and increased contrast in the chromatin drawing
• Increased nuclear-cytoplasmic ratio
• Possible cell dissociation

Grade III urothelial carcinoma - voided urine

• Cellularity is markedly increased 
• Malignant cells can be observed singly, in clusters and in syncytial groups
• Possible cell-in-cell arrangements
• Polymorphic nuclei with coarse chromatin
• Large nucleoli
• Mitotic figures
• The background usually shows evidence of necrosis

Grade III urothelial carcinoma – bladder washing

• Large variations in nuclear size
• Large nuclei without cytoplasm
• Nuclei with irregular shape and bizarre nucleoli
• Usually hyperchromatic nuclei with clumped chromatin but hypochromatic nuclei can also be seen
• Marked increase of the nuclear-cytoplasmic ratio
• Dissociated tumour cells