Table of Contents
Definition / general | Clinical features | Treatment | Microscopic (histologic) description | Microscopic (histologic) images | Differential diagnosisCite this page: Arora K. Urothelial carcinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/prostateurothelial.html. Accessed January 19th, 2021.
Definition / general
- Rare (< 2% of primary tumors) as primary in prostate (without bladder involvement); arises from urothelium in periurethral ducts that is histologically identical to bladder tumors
- Immunostains:
- Urothelial carcinoma in prostatic ducts may have confusing PSA / PAP staining, since residual ducts are immunoreactive, but PSA / PAP does not stain urothelial carcinoma cells (Am J Clin Pathol 2000;113:383)
- Strategies to confirm urothelial carcinoma and rule out high grade prostatic adenocarcinoma:
- CK7+ / CK20+
- p63+ / p501S- (Diagn Pathol 2011 Jul 21;6:67)
- PSA (-) as initial marker (Am J Surg Pathol 2007;31:1246)
- PSA (-), PSAP (-), 34betaE12 (+); then Leu7 (-), CK7(+) (Mod Pathol 2000;13:1168)
- Uroplakin III+ or thrombomodulin+ (Hum Pathol 2002;33:1136)
Clinical features
- Patient history is often bladder carcinoma in situ treated with intravesical chemotherapy (chemotherapy doesn’t reach prostatic urethra, prostatic ducts and acini), or patients with invasive bladder carcinoma and prostate gland involvement (occurs in 45% of cases, J Urol 2002;167:502, Actas Urol Esp 2012;36:545)
- Usually invades bladder neck and surrounding soft tissue
- 20% have distant metastases, commonly to bone, lung, liver
- Bone metastases usually osteolytic, not osteoblastic
- Poor prognosis even with in-situ disease only
Treatment
- Cystoprostatectomy, possibly chemotherapy, radiation therapy
- Note: 50% with cystoprostatectomy for urothelial carcinoma also have prostate adenocarcinoma, although not necessarily high grade
Microscopic (histologic) description
- In situ component usually present, consisting of nests of neoplastic cells filling prostatic ducts, often with central comedonecrosis
- Stromal invasion almost always present and characterized by small nests of tumor cells with marked anaplasia and frequent mitotic figures, even compared to poorly differentiated prostatic adenocarcinoma
- In prostate needle biopsies, often see in-situ only or in-situ plus invasion
- Invasive urothelial carcinoma only is rare (9%)
- Note: prostatic adenocarcinoma may have focal urothelial carcinoma features (Appl Immunohistochem Mol Morphol 2002;10:231)
- Note: important to identify prostatic stromal invasion in cases with intraductal urothelial carcinoma, especially in patients with low grade bladder tumors, since prognosis is poor
Microscopic (histologic) images
Differential diagnosis
- Bladder extension of urethral carcinoma
- High grade prostatic adenocarcinoma: less nuclear pleomorphism, prominent nucleoli, few mitoses, no / rare necrosis, no / rare pagetoid spread; see immunostains above (Am J Surg Pathol 2001;25:794)