Urethral carcinoma: critical view on contemporary consecutive series

The dog as an animal model for bladder and urethral urothelial carcinoma: Comparative epidemiology and histology

Despite the recent approval of several novel agents for patients with metastatic urothelial carcinoma (UC), survival in this setting remains poor. As such, continued investigation into novel therapeutic options remains warranted. Pre-clinical development of novel treatments requires an animal model that accurately simulates the disease in humans. The aim of the present study was to evaluate the dog as an animal model for human UC. A total of 260 cases of spontaneous, untreated canine primary urethral and urinary bladder UC, were epidemiologically and histologically assessed and classified based on the current 2016 World Health Organization (WHO) tumor classification system. Canine data was compared with human data available from scientific literature. The mean age of dogs diagnosed with UC was 10.22 years (range, 4–15 years), which is equivalent to 60–70 human years. The results revealed a high association between UC diagnosis with the female sex [odds ratio (OR) 3.51; 95% confidence interval (CI) 2.57–4.79; P<0.001], surgical neutering (OR 4.57; 95% CI 1.87–11.12; P<0.001) and breed (OR 15.11 for Scottish terriers; 95% CI 8.99–25.41; P<0.001). Based on the 2016 WHO tumor (T), node and metastasis staging system, the primary tumors were characterized as T1 (38%), T2a (28%), T2b (13%) and T3 (22%). Non-papillary, flat subgross tumor growth was strongly associated with muscle invasion (OR 31.00; P<0.001). Irrespective of subgross growth pattern, all assessable tumors were invading beyond the basement membrane compatible with infiltrating UC. Conventional, not further classifiable infiltrating UC was the most common type of tumor (90%), followed by UC with divergent, squamous and/or glandular differentiation (6%). Seven out of the 260 (2.8%) cases were classified as non-urothelial based on their histological morphology. These cases included 5 (2%) squamous cell carcinomas, 1 (0.4%) adenocarcinoma and 1 (0.4%) neuroendocrine tumor. The 2 most striking common features of canine and human UC included high sex predilection and histological tumor appearance. The results support the suitability of the dog as an animal model for UC and confirm that dogs also spontaneously develop rare UC subtypes and bladder tumors, including plasmacytoid UC and neuroendocrine tumor, which are herein described for the first time in a non-experimental animal species.

A Challenging Surgical Approach to Locally Advanced Primary Urethral Carcinoma: A Case Report and Literature Review

Primary urethral carcinoma (PUC) is a rare and aggressive cancer, often underdetected and consequently unsatisfactorily treated. We report a case of advanced PUC, surgically treated with combined approaches.A 47-year-old man underwent transurethral resection of a urethral lesion with histological evidence of a poorly differentiated squamous cancer of the bulbomembranous urethra. Computed tomography (CT) and bone scans excluded metastatic spread of the disease but showed involvement of both corpora cavernosa (cT3N0M0). A radical surgical approach was advised, but the patient refused this and opted for chemotherapy. After 17 months the patient was referred to our department due to the evidence of a fistula in the scrotal area. CT scan showed bilateral metastatic disease in the inguinal, external iliac, and obturator lymph nodes as well as the involvement of both corpora cavernosa. Additionally, a fistula originating from the right corpus cavernosum extended to the scrotal skin. At this stage, the patient accepted the surgical treatment, consisting of different phases. Phase I: Radical extraperitoneal cystoprostatectomy with iliac-obturator lymph nodes dissection. Phase II: Creation of a urinary diversion through a Bricker ileal conduit. Phase III: Repositioning of the patient in lithotomic position for an overturned Y skin incision, total penectomy, fistula excision, and "en bloc" removal of surgical specimens including the bladder, through the perineal breach. Phase IV: Right inguinal lymphadenectomy.The procedure lasted 9-and-a-half hours, was complication-free, and intraoperative blood loss was 600 mL. The patient was discharged 8 days after surgery. Pathological examination documented a T4N2M0 tumor. The clinical situation was stable during the first 3 months postoperatively but then metastatic spread occurred, not responsive to adjuvant chemotherapy, which led to the patient's death 6 months after surgery.Patients with advanced stage tumors of the bulbomembranous urethra should be managed with radical surgery including the corporas up to the ischiatic tuberosity attachment, and membranous urethra in continuity with the prostate and bladder. Neo-adjuvant treatment may be advisable with the aim of improving the poor prognosis, even if the efficacy is not certain while it can delay the radical treatment of the disease.

Primary enteric-type mucinous adenocarcinoma of the urethra in a patient with ulcerative colitis

Primary carcinoma of the male urethra accounts for less than 1% of malignancies in men. Mucinous adenocarcinoma of the urethra is extremely rare, and its biologic behavior is poorly understood. We present herein a rare case of mucinous urethral adenocarcinoma in a male patient with longstanding ulcerative colitis and multiple sclerosis. The patient presented with a voluminous pelvic mass; core biopsy of the lesion demonstrated a mucus-producing adenocarcinoma. Given the patient's history of subtotal colectomy, preoperative diagnosis was oriented towards a rectal stump adenocarcinoma. The patient underwent a pelvic exenteration: surprisingly, histology marked the prostatic urethra as the primary lesion site.

Secondary mucinous adenocarcinoma of the prostate in a patient with ulcerative colitis

Herein we report a rare case of prostatic invasion of rectal carcinoma in a patient with ulcerative colitis. Malignant transformation is a well-known complication of long-standing ulcerative colitis. Mucinous adenocarcinoma, with positive carcinoembryonic antigen and negative prostate-specific antigen, strongly suggested the rectal origin of the tumor.