Malignant anterior urethral strictures: a rare complication of transurethral resection of malignant prostate

Multiple metastases of androgen indifferent prostate cancer in the urinary tract: two case reports and a literature review

BACKGROUND

Prostate cancer (PC) is mainly known to metastasize to bone, lung and liver, but isolated metastases of prostate cancer, including ductal carcinoma, in the urinary tract are very rare. We describe two patients with nodular masses in the urinary tract (the anterior urethra or the urinary bladder) that were found on cystoscopy during treatment of castration-resistant prostate cancer.

CASE PRESENTATION

In both cases, the pathological diagnosis from transurethral tumor resection showed that they were androgen indifferent prostate cancer (AIPC), including aggressive variant prostate cancer (AVPC) in Case 1 and treatment-induced neuroendocrine differentiation prostate cancer (NEPC) in Case 2. In Case 1, Loss of genetic heterozygosity (LOH) of BRCA2 and gene amplification of KRAS was identified from the urethra polyps. In Case 2, homozygous deletion was observed in PTEN, and LOH without mutation was observed in RB1.

CONCLUSION

These are the first reports of two cases of urinary tract metastasis of AIPC.

Unusual presentation of castrate-resistant prostate cancer with urethral and inguinal nodal metastasis

Metastatic involvement of the urethra is a rare finding in patients with carcinoma prostate. The signs and symptoms overlap with those of a primary urethral malignancy. The diagnosis is made following a biopsy of the suspected lesions. We describe the case of a 66-year-old patient with carcinoma prostate who presented with penile pain, 18 months after the treatment with androgen deprivation therapy. Ga-68 prostate-specific membrane antigen positron emission tomography/computed tomography helped in the identification of the urethral and inguinal nodal metastasis, which was confirmed histologically. We also discuss the management of this unusual clinical scenario.

Isolated anterior urethral recurrence of prostatic adenocarcinoma

Isolated anterior urethral metastases from prostate cancer are rare. The pathogenesis of this form of loco-regional recurrence may be related to spread by instrumentation-induced implantation and could potentially then be associated with a better prognosis than metastatic disease secondary to a more malignant phenotype. We report a case of a 68-year-old man with high-risk prostate cancer, diagnosed at transurethral resection of prostate, who was originally treated with combination external beam radiotherapy and hormonal therapy. He re-presented 4 years after his original diagnosis with recurrent gross hematuria and cystourethroscopic biopsies of anterior urethral polyps revealing isolated recurrent prostatic adenocarcinoma. We present our this case and review the literature.

Isolated recurrence of ductal prostate cancer to anterior urethra

We report the case of a 74-year-old man with ductal prostate cancer who had originally undergone radiotherapy but developed metastases to the anterior urethral mucosa. This is the fourth such case ever reported in English publications. We suspect the metastases developed from implantation after instrumentation, a common finding in the previously reported cases. Although no specific treatment regimen exists, we believe that local resection followed by androgen deprivation is the treatment of choice in these patients.