Mucinous Carcinoma Metastatic to Prostate

Case Posted 11.6.2002

Diagnosis

Mucinous carcinoma of the urinary bladder, invasive into the prostate

Discussion

This is a fascinating case with the final diagnosis put together after a discussion with the referring urologist. The original needle core biopsy demonstrated a mucinous carcinoma. The differential diagnosis was between a primary mucinous carcinoma of the prostate versus a metastatic mucinous carcinoma with possible primary sites including the gastrointestinal tract and urinary bladder. The strong immunopositivity for CEA and negative findings for PSA still pointed to a metastases from either the GI tract or bladder. A discussion with the urologist revealed that after the needle biopsies were taken, a large tumor apparently arising from the urinary bladder and directly invading into the prostate was readily evident. The patient was taken to surgery the following day for a radical cystectomy and prostatectomy. The final pathology was a primary mucinous carcinoma of the urinary bladder, invasive through the wall of the bladder and invading into the prostate gland.

The paper cited below examined cases of primary mucinous carcinomas of the urinary bladder arising from the prostatic urethra and compared them to cases of primary mucinous carcinomas of the prostate. In this study, the mucinous adenocarcinomas of the prostate demonstrated tubules and cribriform glands floating within mucin with only rare mucin-positive signet cells. The bladder tumors were positive for CEA and negative for PSA and PAP. An in situ component was identified within the prostatic urethra in one case. However, the morphologic distinction between the two types of tumors may be difficult.

References

Urinary Bladder Carcinoma

Tran KP, Epstein JI. Mucinous adenocarcinoma of urinary bladder type arising from the prostatic urethra. Distinction from mucinous adenocarcinoma of the prostate. Am J Surg Pathol 1996 Nov;20(11):1346-50.

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Last Updated 11/6/2002