Bladder
Adenocarcinoma
Adenocarcinoma-Urachal

Author: Rugvedita Parakh, M.D. (see Authors page)

Revised: 1 August 2016, last major update December 2014

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed Search: Bladder [title] urachal adenocarcinoma
Definition / General
    Criteria for urachal origin of adenocarcinoma:
  • Centered in anterior wall or dome of bladder
  • Predominant invasion of muscularis or deeper tissues with sharp demarcation between tumor and surface bladder urothelium
  • Surface urothelium is free of glandular or polypoid proliferation (i.e. invasion is from outside in)
  • No carcinoma in situ or glandular metaplasia other than (possibly) cystitis glandularis is present
  • The presence of urachal remnants is helpful but not always identifiable
  • No primary adenocarcinoma elsewhere

  • Represents 10-30%of bladder adenocarcinomas, 0.3% of all bladder cancers
Sites
  • Usually dome of bladder; occasionally anterior wall of bladder
Etiology
  • The urachus is the embryological remnant of the urogenital sinus and allantois, connecting the bladder to the umbilicus; involution usually happens before birth and the urachus becomes a fibrous cord known as the median umbilical ligament, which is not part of the adult bladder
  • Remnants of the allantois may persist and develop into cysts or epithelial neoplasms
  • Urachus - drawing
Clinical Features
  • Staging may be difficult, since arises in bladder wall
  • 40-50% recur locally
  • Metastasizes to lymph nodes, lungs, peritoneal cavity, liver and bone
  • Compared to non-urachal adenocarcinoma, patients/tumors are slightly younger (median age 56 vs. 69 years), less likely high grade (35% vs. 66%), distant metastases are more common (30% vs. 15%), but better survival (Cancer 2006;107:721)

    Sheldon staging system:
  • pT1-no invasion beyond the urachal mucosa (i.e. in situ)
  • pT2-invasion confined to the urachus
  • pT3-local extension to the (a) bladder, (b) abdominal wall, and (c) viscera other than the bladder
  • pT4-metastasis to (a) regional lymph nodes and (b) distant sites

References: (J Urol 1984;131:1)
Prognostic Factors
  • Poor prognosis (5 year survival of 50%) since diagnosed late in course of disease due to growth in a clinically silent space (between bladder and umbilicus)
  • Prognostic factors are tumor stage and histologic differentiation (Hum Pathol 1996;27:240)
Case Reports
Treatment
Clinical Images

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Intraoperative image of suprapubic mass

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Intraoperative image of cystic lesion at dome of bladder

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Intraoperative image of urachal cyst

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Intraoperative image of multilobulated cyst

Gross Description
  • Arises in dome of bladder or anterior bladder or beneath anterior abdominal wall between umbilicus and bladder dome
  • Tumor may occur anywhere along urachal tract
Gross Images

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Tumor removed en bloc with umbilicus

Micro Description
  • Epicenter is in bladder wall
  • Tumor is sharply demarcated from normal epithelium
  • Most tumors arise from intramural portion of urachus, grow into bladder wall, may lack mucosal involvement
  • Usually well-differentiated, mucin-producing adenocarcinomas
  • Often enteric type; also colloid type (tumor cells float in mucin lakes), features of lymphoepithelioma-like carcinoma, urothelial carcinoma, signet-ring cell carcinoma
  • Often NO intestinal metaplasia
Micro Images

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Mucinous cystadenocarcinoma

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Differentiated tumor in muscularis propria

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Vertebral metastasis of above tumor

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Tumor has variable
staining for CDX2,
and is CK7+, CK20+


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In situ tumor with no evidence of invasion

Positive Stains
Differential Diagnosis
  • Local extension of colonic or other adenocarcinoma: clinical history is important; diffuse positivity for 34BE12 supports urachal carcinoma, diffuse nuclear immunoreactivity for beta-catenin suggests not urachal carcinoma (Am J Surg Pathol 2009;33:659)
  • Metastatic adenocarcinoma: clinical history is important
  • Nonurachal adenocarcinoma of bladder: intraluminal mass, carcinoma in situ or extensive glandular metaplasia of adjacent urothelium
  • Villous adenoma: noninvasive