Papillary Lesions of the Bladder

Question 1

What must be present in order to

diagnose a papillary lesion of the bladder?

Answer 1

• must have true FVCs
• without well-formed papillae a diagnosis of a neoplasm should not be made

Question 2

What is a common diagnostic pitfall

in papillary neoplasms ?

Answer 2

• Papillary/Polypoid cystitis
  
  • classic morphology are broad, edematous folds of urothelial mucosa and lamina propria
  • chronic inflammation is present in lamina propria and the mucosa
  • generally seen with recent injury from a catheter or stone

IMP: unlike a true papillary neoplasm there are no fibrovascular cores

Question 3

What are the features of papillary

urothelial hyperplasia ?

Answer 3

• wave-like periodicity to the mucosal folds
• corrugated appearance of the urothelium
• lack true FVC
  
  • DO NOT be fooled by small capillaries at the tips
• may be a precursor lesion (seen associated with) low-grade papillary urothelial neoplasia
• urothelium may be thickened but there will be no significant atypia

Question 4

What are the diagnostic features

of a urothelial papilloma ?

Answer 4

• fibrovascular cores must be evident
• the papillary lesions are normal thickness (5-7 cell layers)
• lack atypia of the nuclei
• papillary fronds are usually very slender and long
• seen in younger patients
• rarely progress to higher lesions

Question 5

What are the diagnostic features

of PUNLMP ?

Answer 5

• papillary lesion with minimal atypia and minimal architectural disorganization
• lesions are slightly more eosinophilic than papilloma (which looks more clear)
• mild nuclear atypia may be present:
  
  • hyperchromasia, loss of nuclear grooves, enlarged nuclei
• infrequent mitosis and basally located
• papillae are short and thicker
• 20% of them recur (mostly as low grade) but some recur as high grade urothelial carcinoma

Question 6

How is PUNLMP differentiated from

Low grade papillary urothelial carcinoma ?

Answer 6

• by the degree of atypia present

Question 7

What are the diagnostic criteria for

Low-grade papillary urothelial carcinoma?

Answer 7

• thickened papillae with FVC
• thickened urothelium
• enlarged nucle with scattered atypical cells, loss of grooves
• increased mitosis
• moderate architectural disarray (loss of nuclear polarity)

Question 8

What are the features of high

grade urothelial carcinoma?

Answer 8

• severe atypia and marked architectural disarray
• papillary fronds are thickened and some may be blunted with complex architectural branching
• cytology:
  
  • increased N:C ratio
  • hyperchromatic nuclei with clumped chromatin
  • irregular nuclear membranes
  • mitotic figures are easily identifiable
• also has a tendency for denudation