Urothelial carcinomas or transitional cell carcinomas of the prostate are malignant neoplasms that can occur as primary cancers of the prostate gland.
Prostatic urothelial carcinomas account for less than 2-4% of all prostate cancers 1 and are usually seen in middle-aged men 2.
Typical symptoms include hematuria and voiding symptoms as irritation, dysuria or other obstructive symptoms 2,3. The digital rectal examination might reveal an enlarged and/or hard prostate. Prostate-specific antigen (PSA) should not be elevated 3.
Prostatic urothelial carcinomas can metastasize to bone, lung or liver. Bony metastases are typically osteolytic.
Prostatic urothelial carcinomas are mainly diagnosed based on features from histopathology and immunohistochemistry 3.
Urothelial carcinomas of the prostate typically originate from the prostatic urethra or the prostatic ducts 3.
Microscopically prostatic urothelial carcinomas are characterized by the following histological features 3:
- tendency to ductal growth
- solid cylinders
- possible central comedo necrosis
- nuclear polymorphism
- frequent mitoses
- stromal invasion with cords nests and desmoplastic response
Urothelial carcinomas of the prostate express urothelial cell markers as GATA3, CK7 or P63 on immunohistochemistry stains. They should be negative for prostatic cell markers as prostatic-specific antigen or NKX3-1 2,3.
Urothelial carcinomas have been described as infiltrative but otherwise uncharacteristic 3.
- T2: mildly hyperintense
- DWI: heterogeneously hyperintense on high b-value with moderate low signal intensity on ADC
- DCE (Gd): avid enhancement
The radiological report should include a description of the following features:
- form, location and size
- tumor margins
- bladder or urethral invasion
- suspicious or enlarged lymph nodes
- any concomitant prostate cancer
Treatment and prognosis
Their prognosis is good as long as they occur in isolation as carcinoma in situ 3. If they occur in association with transitional carcinomas of the bladder or urethra their prognosis is poor with an estimated 5-year survival of 35-40% 3. Management strategy is usually multimodal and includes surgery including cystoprostatectomy as well as adjuvant radiotherapy and chemotherapy 3.
Transurethral resection and instillation of Bacillus Calmette-Guérin (BCG) can be performed in carcinoma in situ 4.
History and etymology
Urothelial carcinomas of the prostate were first described by Norman Ende et. al in 1963 2,4.
Conditions mimicking the clinical presentation or imaging appearance of prostatic urothelial carcinoma include 1:
- invasive prostate adenocarcinoma
- urethral polyp
- neuroendocrine tumors of the prostate
- mesenchymal tumors of the prostate
- 1. Li Y, Mongan J, Behr SC, Sud S, Coakley FV, Simko J, Westphalen AC. Beyond Prostate Adenocarcinoma: Expanding the Differential Diagnosis in Prostate Pathologic Conditions. (2016) Radiographics : a review publication of the Radiological Society of North America, Inc. 36 (4): 1055-75. doi:10.1148/rg.2016150226 - Pubmed
- 2. Zhou J, Yang C, Lu Z, Zhang L, Yin Y, Tai S, Liang C. Primary urothelial carcinoma of the prostate: A rare case report. (2019) Medicine. 98 (3): e14155. doi:10.1097/MD.0000000000014155 - Pubmed
- 3. Inamura K. Prostatic cancers: understanding their molecular pathology and the 2016 WHO classification. (2018) Oncotarget. 9 (18): 14723-14737. doi:10.18632/oncotarget.24515 - Pubmed
- 4. Gakis G, Bruins HM, Cathomas R, Compérat EM, Cowan NC, van der Heijden AG, Hernández V, Linares Espinós EE, Lorch A, Neuzillet Y, Ribal MJ, Rouanne M, Thalmann GN, Veskimäe E, Witjes AJ. European Association of Urology Guidelines on Primary Urethral Carcinoma-2020 Update. (2020) European urology oncology. 3 (4): 424-432. doi:10.1016/j.euo.2020.06.003 - Pubmed
- 5. Ende N, Woods LP, Shelley HS. Carcinoma originating in ducts surrounding the prostatic urethra. (1963) American journal of clinical pathology. 40: 183-9. doi:10.1093/ajcp/40.2.183 - Pubmed