Papillary cystadenocarcinoma of the prostate: a case report

A 91-year-old man presented with nocturnal frequency and urge incontinence of a few days duration due to involvement of prostate cancer (PCa) accompanied by a large cyst in the left lobe of the prostate gland and urinary bladder wall. Channeling transurethral resection of prostate was performed to relieve the main symptoms and the resected material was histologically diagnosed as papillary cystadenocarcinoma arising from the epithelium of microscopic retention cysts. Following shrinkage of the large cyst, the patient is doing well on a combination regimen of a luteinizing hormone-releasing hormone analogue and bicaltamide. Papillary cystadenocarcinoma of the prostate was originally defined as papillary PCa arising from, not accompanied by, prostatic cysts. Cysts associated with PCa are subdivided into primary (or true) and secondary (or pseudo) cysts. Cancer cells in primary cysts originate from the epithelial lining. Papillary growth type cysts belong to this group and are regarded as papillary cystadenocarcinoma. The secondary (or pseudo) cysts, which have no epithelial lining and consist of hemorrhagic and/or necrotic contents are associated with invasive PCa. In the present case, the microscopic retention cysts revealed by histologic examination were of the primary type. This case of papillary cystadenocarcinoma, arising from a primary cyst, is the 13th such report from among previously reported cases in Japan.