Primary signet ring cell carcinoma of the prostate treated by radical cystoprostatectomy and chemoradiotherapy.

Primary signet ring cell carcinoma (SRCC) of the prostate is very rare. Although SRCC is primarily found in the stomach and colon, it can also be found in the pancreas, breast, thyroid, bladder, and prostate. We recently diagnosed and treated a case of primary SRCC of the prostate. A 56-year-old Korean man was referred to our institution for evaluation of a one-month history of hematuria and recently identified bladder mass. Transurethral resection of the bladder tumour was performed and histological and immunohistochemical evaluation revealed a diagnosis of SRCC with tumour invading into the outer half of the deep muscularis propria. After three weeks, the patient had radical cystoprostatectomy with ileal conduit. Tumour involved both prostate and bladder, but the centre of the tumour was located in the prostate. Duodenoscopy and colon fibroscopy both indicated no evidence of tumour origin in the gastrointestinal (GI) tract. Overall, this tumour was regarded as primary SRCC of the prostate. Concurrent chemoradiotherapy (CCRT) using leucovorin and fluorouracil was initiated two months later. The patient eventually developed bone and liver metastases and died of hepatopathy.