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Bladder
Other Carcinomas
Adenocarcinoma-Urachal
Author: Nat Pernick, M.D. (see Authors page)
Revised: 23 December 2009, last major update - December 2009
Copyright: (c) 2002-2009, PathologyOutlines.com, Inc.
Definition
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● 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 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
Terminology
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Epidemiology
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● Mean age 52 years but wide age range; no gender preference
Sites
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● Usually dome of bladder; occasionally anterior wall of bladder
Etiology
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● 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
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● 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
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● 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 Path 1996;27:240)
Case reports
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● 30 year old woman with vertebral metastasis (Archives 2004;128:1043)
● 45 year old man with 11 cm tumor (World J Surg Oncol 2009 Nov 7;7:82)
● 54 year old man with in situ adenocarcinoma of the urachus arising in a giant urachal cyst, and associated pseudomyxoma peritonei (J Clin Pathol 2003;56:152)
● 55 year old man with enteric type tumor (Can J Urol 2009;16:4753)
● 55 year old man with mucinous colloid adenocarcinoma of urachus (RadioGraphics 2001;21:965)
● 58 year old man with mucinous urachal cystadenocarcinoma and pseudomyxoma peritonei (Magn Reson Med Sci 2009;8:85)
● 68 year old man (Bostwick Laboratories)
● Signet-ring cell type with linitis plastica growth (Archives 1981;105:203)
Treatment
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● Umbilectomy with partial cystectomy, possibly laparoscopic (Clinics (Sao Paulo) 2008;63:731); must excise entire tract of median umbilical ligament
Clinical images
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Axial CT image shows a large, predominantly solid, midline mass with peripheral calcifications (arrowheads); within the mass are scattered low-attenuation areas (arrows), which represent mucin, link
Cystoscopy demonstrates an area of ulceration at the bladder dome (arrow) in a background of normal pink bladder mucosa, link
Intraoperative image of suprapubic mass, link
Intraoperative image of cystic lesion at dome of bladder, link
Intraoperative image of urachal cyst, link
Intraoperative image of multilobulated cyst, link
Gross description (Macroscopy)
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● 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, lateral umbilical ligaments, adjacent peritoneum and bladder dome, link
Surgical resection extended from bladder dome mass (arrowheads) to umbilicus (arrow), link
Polypoid ulcerated mass, link
Cystic mass with hemostat on umbilicus (arrow), link
White mucinous center (black arrow) of cystic component; dome of the bladder is indicated by white arrow, link
Cut surface shows a glistening surface, link
Cut surface shows a large intramural mucinous mass, link
Tumor contains white gelatinous material, link
Micro description (Histopathology)
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● 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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Colloid type adenocarcinoma; mucin and tumor cells dissect through muscularis propria;
Adenocarcinoma involves bladder wall with large lakes of mucin (arrows); bladder mucosa (arrowhead) is normal, link
Signet-ring and colloid components, link
Mucinous cystadenocarcinoma with invasion and mucin extravasation, link
Papillary and glandular patterns;
Moderately differentiated tumor in muscularis propria, link
Vertebral metastasis of above tumor, link
Complex mucin-secreting epithelium (black arrow), link
Tall simple to pseudostratified columnar epithelium, including goblet cells, link
May resemble colonic adenocarcinoma, link
Mucin production and intestinal-like epithelium, link
Tumor has variable staining for CDX2, and is CK7+, CK20+, link
In situ tumor with no evidence of invasion, #1; #2
Cytology description
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●
Cytology images
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Videos
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● 55 year old man with robotic surgery
Positive stains
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● CK7; variable CK20 and CDX2
Negative stains
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●
Electron microscopy descriptions
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●
Electron microscopy images
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Molecular / cytogenetics description
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●
Molecular / cytogenetics images
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Differential Diagnosis
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● 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
Additional references
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●
End of Bladder > Other Carcinomas > Adenocarcinoma-urachal
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