Bladder

Question 1

Bladder lesion with sheets of histiocytes with granular eosinophilic cytoplasm (von Hansemann cells), containing round basophilic cytoplasmic inclusions (Michaelis-Gutmann bodies) that look like archery targets.

Answer 1

Malakoplakia

Plan:
Correlate with clinical history and radiology (?immunosupression ?history of urinary infection)
Special stains: Von Kossa (to highlight Michaelis-Guttman bodies)

Question 2

Endophytic growth of normal thickness urothelium (≤ 7 cells) forming anastomosing cords, islands and trabeculae. Cells are bland with preserved polarity.

Answer 2

Inverted urothelial papilloma

Differential diagnosis:
Florid von Brunn nest proliferation
Carcinoid tumour

Plan:
Correlate with clinical history and cystoscopic impression
IPX to support Dx: Not required
IPX to discount DDx: Synaptophysin, chromogranin
No specific further action required for this benign diagnosis.

Question 3

Bladder lesion with multiple small tubules in superficial lamina propria lined by cuboidal to columnar (sometimes ‘hobnail’) cells. Tubules surrounded by a thickened hyalinized basement membrane. Can also show polypoid / papillary growth. Lacks desmoplastic stromal response, necrosis, or mitosis

Answer 3

Nephrogenic metaplasia / adenoma

Differential diagnosis:
Clear cell adenocarcinoma
Rule out urothelial carcinoma and prostatic adenocarcinoma

Plan:
Correlate with clinical history and cystoscopic impression (?history of bladder instrumentation or infection ?renal transplant)
IPX to support Dx: AE1/AE3, PAX8 (expect positive)
IPX to discount DDx: CAIX, GATA3, NKX3.1
No specific further action required for this benign diagnosis

Question 4

Bladder wall containing calcified eggs surrounded by granulomatous inflammation rich in eosinophils. Squamous metaplasia may also be present.

Answer 4

Schistosomiasis

Plan:
Correlate with clinical history and cystoscopic findings (?migration from or travel to endemic area)
Examine further blocks (e.g. for associated squamous metaplasia / carcinoma)
Advice to clinician (urgent via phone): This is a rare infectious disease in Australia. Patient may require urgent treatment.

Question 5

Urethral lesion with cloverleaf-like and club-like projections covered by normal urothelium, with florid cystitis cystica et glandularis within the dense fibrovascular stroma

Answer 5

Fibroepithelial urethral polyp

Differential diagnosis:
Urothelial papilloma (slender, delicate fibrovascular cores)
Polypoid urethritis (oedematous, broad based inflamed cores)

Plan:
Correlate with clinical history and radiology (?site within urethra ?history of instrumentation/trauma)
No further action required for this benign diagnosis