title: Primary mucin-producing urothelial-type adenocarcinoma of the prostatic urethra diagnosed on TURP: a case report and review of literature.
abstract: BACKGROUND
  Mucin-producing urothelial-type adenocarcinoma of the prostatic urethra is extremely rare. These lesions must be differentiated from other mucinous tumors including mucin-producing prostatic adenocarcinoma and metastases from either colonic or bladder primaries.
  
  
  METHODS
  We report here a case of urothelial-type adenocarcinoma arising from the prostatic urethra. The patient is an 81 year-old man with a history of pT1 urothelial cell carcinoma of the bladder status post trans-urethral resection of bladder tumor (TURBT) who initially presented with irritative lower urinary tract symptoms and mucosuria refractory to Flomax and finasteride. A shared decision was made for the patient to undergo trans-urethral resection of prostate (TURP). At the time of surgery, a papillary tumor emanating from the prostatic urethra was found and no urothelial lesions were noted in the bladder. Pathology of the resected prostatic chips revealed an invasive adenocarcinoma with intestinal-type differentiation that stained positive for CK7, CK20, and villin, but negative for PSA, PSAP, uroplakin, and CDX-2. Colonoscopy was normal and CT scan did not show any evidence of colonic lesions nor visceral or lymph node metastases. Thus, the patient was diagnosed with a primary urothelial-type adenocarcinoma of the prostatic urethra.
  
  
  CONCLUSIONS
  Herein we review the literature regarding this unusual entity, and discuss the differential diagnosis, immunohistochemistry, and the importance of correctly identifying this rare tumor.
authors.affiliation: Columbia University College of Physicians and Surgeons, 630 W, 168th St, New York, NY 10032, USA. ems2230@columbia.edu.
authors.forename: Elisabeth M
authors.initials: EM
authors.lastname: Sebesta
authors.forename: Hossein S
authors.initials: HS
authors.lastname: Mirheydar
authors.forename: J Kellogg
authors.initials: JK
authors.lastname: Parsons
authors.forename: Jessica
authors.initials: J
authors.lastname: Wang-Rodriguez
authors.forename: A Karim
authors.initials: AK
authors.lastname: Kader
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology* / Q000601:surgery*; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D009077:Mucins / Q000378:metabolism*; D020728:Transurethral Resection of Prostate; D014523:Urethral Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery
chemical_list: D009077:Mucins