DOI: 10.1148/radiol.2223001470
(Radiology 2002;222:744-747.)
© RSNA, 2002
Case 44: Adenocarcinoma of the Urachus1
Bernard Mengiardi, MD,
Walter Wiesner, MD,
Flavio Stoffel, MD,
Luigi Terracciano, MD and
Peter Freitag, MD
1 From the Departments of Radiology (B.M., W.W., P.F.), Surgery/Urology (F.S.), and Pathology (L.T.), University Hospital Basel, Switzerland. Received August 29, 2000; revision requested October 5; revision received November 20; accepted January 8, 2001. Address correspondence to B.M., Michelstrasse 22, CH-8049 Zurich, Switzerland (e-mail: mengiardi@yahoo.de).
Index terms: Adenocarcinoma, 831.324, 839.324 • Bladder neoplasms, 831.324 • Diagnosis Please • Urachus, 839.324
 |
HISTORY
|
|---|
A 46-year-old man presented with a history of dysuria and gross hematuria of 3 weeks duration. Physical examination findings were normal. The white and red blood cell counts were normal. Urinalysis showed pyuria and hematuria, but all urine cultures were negative for bacteria. Ultrasonography (US) of the urinary bladder and contrast material–enhanced computed tomography (CT) were performed (Figs 1, 2).
View larger version (113K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 1. Midline sagittal ultrasonogram through the dome of the bladder (4 MHz, phased array). There is a large mass with inhomogeneous echotexture that protrudes into the superior surface of the bladder (arrows).
|
|
View larger version (104K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2a. Contrast-enhanced transverse helical CT scans through the pelvis (7-mm collimation, 5-minute scanning delay). (a) A cystic mass (arrows) at the anterior dome of the bladder is visible. (b) Dystrophic calcifications (arrowheads) within the solid portions of the tumor are suggestive of a mucinous adenocarcinoma.
|
|
View larger version (109K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2b. Contrast-enhanced transverse helical CT scans through the pelvis (7-mm collimation, 5-minute scanning delay). (a) A cystic mass (arrows) at the anterior dome of the bladder is visible. (b) Dystrophic calcifications (arrowheads) within the solid portions of the tumor are suggestive of a mucinous adenocarcinoma.
|
|
|
IMAGING FINDINGS
|
|---|
US examination of the urinary bladder revealed a large solitary midline soft-tissue mass located ventral and superior to the urinary bladder with areas of diminished echogenicity (Fig 1). Contrast-enhanced CT confirmed the findings seen at US and showed a large partially cystic contrast-enhancing mass in the space of Retzius at the anterior dome of the bladder (Fig 2a). CT showed some tiny dystrophic calcifications within the solid portions of the tumor that were suggestive of a mucinous adenocarcinoma (Fig 2b).
|
DISCUSSION
|
|---|
The radiologic differential diagnosis in this case included infected benign cyst of the urachus, primary adenocarcinoma of the urinary bladder, and metastatic or infiltrating adenocarcinoma originating mostly from primary lesions of the colon or the prostate or the female genital tract. Desmoid tumors may be located in the same region but usually do not have a cystic appearance. Nonurachal neoplasms of the vesical dome are much less likely to extend anteriorly outside the bladder, to be located in the midline, or to contain calcifications. These primary vesical carcinomas typically have a small, if any, extravesical component and predominantly show an intravesical growth of the tumor (1–3). The finding of a supravesical midline mass in the space of Retzius points to a urachal origin, and the presence of a stippled calcification can be considered highly suggestive of a mucinous adenocarcinoma of the urachus (4). Results of intravenous urography are usually normal, although unspecific deformity of the bladder dome and, in later stages, even ureteric deviation may be observed (5).
An infiltrating tumor at the dome of the bladder was confirmed at cystoscopy and surgery (Fig 3). Biopsy findings revealed cells of a well-differentiated mucinous adenocarcinoma (Fig 4), which could be classified as carcinoma of the urachus on the basis of the typical location and characteristic radiologic appearance.
View larger version (114K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 3a. Intraoperative findings. (a) Cranial to caudal view onto the bladder dome. The tumor (arrows) which is situated in the space of Retzius shows continuity with the urachal remnant known as the median umbilical ligament (arrowheads). (b) View inside the opened urinary bladder (arrowheads) demonstrates the infiltrative tumor (arrows) at the dome of the bladder.
|
|
View larger version (124K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 3b. Intraoperative findings. (a) Cranial to caudal view onto the bladder dome. The tumor (arrows) which is situated in the space of Retzius shows continuity with the urachal remnant known as the median umbilical ligament (arrowheads). (b) View inside the opened urinary bladder (arrowheads) demonstrates the infiltrative tumor (arrows) at the dome of the bladder.
|
|
The patient underwent a partial cystectomy with en bloc resection of the tumor, the median umbilical ligament (urachal remnant), and the umbilicus (Fig 3). Additionally, a pelvic lymphadenectomy was performed.
Adenocarcinoma of the urachus is a rare neoplasm, which accounts for only 0.01% of all adult cancers and for 0.17%–0.34% of all carcinomas of the bladder; the estimated annual incidence of this neoplasm is 1 case in 5 million of the general population per year (6). The tumor has a male predilection (65%–75% of all cases) and is most commonly found in patients between the ages of 40 and 70 years (65% of all cases) (1). Of all cancers of the urachus, 85%–90% are adenocarcinomas, and 34% of all primary adenocarcinomas of the urinary bladder originate in the urachus (7). Rarely, cancers of the urachus are transitional cell carcinomas, sarcomas, or squamous cell carcinomas (8).
Between the 2nd and 4th embryonal month, the ventral portion of the cloaca develops into the fetal bladder. The urachus represents the narrowed apex which is continuous with the allantoic stalk at the umbilicus. The urachus obliterates later and becomes a midline fibrous cord extending from the anterior bladder dome to the umbilicus (2). The cord is known as the median umbilical ligament (Fig 3) (1). Incomplete regression of the urachus may result in a patent urachus, an umbilical sinus, a diverticulum or a cyst of the urachus. The most common complications of these regression anomalies are infections whereas malignant transformation of urachal remnants are much less common (9). The urachal remnant may be divided into a supravesical, an intramural, and an intramucosal portion. Adenocarcinoma of the urachus originates from columnar metaplasia in urachal remnants that are lined most commonly with transitional epithelium (1). Tumors of the urachus usually arise from the upper part of the intramural portion or the lower part of the extravesical portion of the bladder. Therefore, they are situated outside the peritoneum in the space of Retzius, which is bounded by the transverse fascia ventrally and the peritoneum dorsally.
The most common finding with carcinoma of the urachus is hematuria (70%), and less common findings are abdominal pain, suprapubic mass, irritative voiding symptoms, and umbilical discharge of mucus, blood, or pus. Mucus micturition may be suggestive of an adenocarcinoma, but it is reported to occur only in 25% of the cases (8).
As a primary diagnostic maneuver for unclear gross hematuria, cystoscopy reveals a tumor at the dome of the bladder in about 90% of the cases (6). The clinician should think about the possibility of an adenocarcinoma of the urachus when a tumor is found at this location and should initiate further diagnostic imaging.
US and CT usually reveal a solitary midline soft-tissue mass that may be solid, cystic, or mixed. Sixty percent of cases have areas of low echogenicity, which reflects the presence of either necrosis or mucin-containing regions. Contrast enhancement of the tumor at CT is reported to be mostly heterogeneous (1). In 50%–70% of cases, curvilinear, punctate, or stippled calcifications are found, which indicates a mucinous adenocarcinoma, and these calcifications often are located in the tumor periphery (1,3). Conventional radiographs usually have a low sensitivity to demonstrate these intratumoral calcifications, whereas CT allows detection of this finding. If a tumor with inhomogeneous enhancement, cystic components, and punctate calcifications is found at this typical location, the radiologic findings are highly suggestive of adenocarcinoma of the urachus.
In some rare cases, the tumor may even lead to a fistula to the adjacent bowel. In such cases, gas inclusions or even orally administered contrast material may be found within the mass (2).
At magnetic resonance imaging, the tumor is reported to be inhomogeneous and to show high intensity on T2-weighted images. Magnetic resonance imaging has the advantage, over CT, of multiplanar imaging and may be useful to determine clearly the involvement of the urinary bladder or of other adjacent structures, whereas this can be difficult in the transverse plane alone (9).
Extended partial or total cystectomy with en bloc resection of the mass in the urachus and of the umbilicus is the treatment of choice, and local surgical control is crucial to success. Adjuvant radiation therapy does not influence the outcome (10), whereas some promising data exist regarding adjuvant chemotherapy (11).
Local recurrence after surgical treatment of an adenocarcinoma of the urachus is common. Distant metastases tend to occur late and are commonly located in regional nodes, in the omentum, the liver, the lungs, and the bones (4).
Long-term prognosis is considerably worse than for most types of primary carcinomas of the bladder, and the 5-year survival rate is 10%–43% (6,12).
Since long-term prognosis in patients with carcinoma of the urachus depends on not only the grading but also the initial tumor stage, early diagnosis is essential in this rare malignancy.
|
FOOTNOTES
|
|---|
Part 1 of this case appeared 4 months previously and may contain larger images.
|
REFERENCES
|
|---|
-
Brick SH, Friedman AC, Pollack HM, et al. Urachal carcinoma: CT findings. Radiology 1988; 169:377-381.[Abstract/Free Full Text]
-
Korobkin M, Cambier L, Drake J. Computed tomography of urachal carcinoma. J Comput Assist Tomogr 1988; 12:981-987.[Medline]
-
Narumi Y, Sato T, Kuriyama K, et al. Vesical dome tumors: significance of extravesical extension on CT. Radiology 1988; 169:383-385.[Abstract/Free Full Text]
-
Nesbitt JA, Walther PJ. Computed tomographic imaging of microscopic dystrophic calcification in urachal adenocarcinoma. Urology 1986; 27:184-186.[CrossRef][Medline]
-
Cooperman LR. Carcinoma of the urachus with extensive abdominal calcification. Urology 1978; 12:614-616.[CrossRef][Medline]
-
Sheldon CA, Clayman RV, Gonzalez R, Williams RD, Fraley EE. Malignant urachal lesions. J Urol 1984; 131:1-8.[Medline]
-
Ravi R, Shrivastava BR, Chandrasekhar GM, Prahlad S, Balasubramanian KV, Mallikarjuna VS. Adenocarcinoma of the urachus. J Surg Oncol 1992; 50:201-203.[Medline]
-
Dähnert W. Urachal carcinoma In: Radiology review manual. 3rd ed. Baltimore, Md: Williams & Wilkins, 1999; 706-707.
-
Krysiewicz S. Diagnosis of urachal carcinoma by computed tomography and magnetic resonance imaging. Clin Imaging 1990; 14:251-254.[CrossRef][Medline]
-
Jakse G, Jacobi GH, Alwein JE. Das Adenokarzinom der Harnblase. Urologe A 1979; 18:86-90.[Medline]
-
Logothetis CJ, Samuels ML, Ogden S. Chemotherapy for adenocarcinomas of bladder and urachal origin: 5-fluorouracil, doxorubicin, and mitomycin-C. Urology 1985; 26:252-255.[CrossRef][Medline]
-
Henly Dr, Farrow GM, Zincke H. Urachal cancer: the role of conservative surgery. Urology 1993; 42:635-639.[CrossRef][Medline]
Our congratulations to the 161 individuals who submitted the most likely diagnosis (adenocarcinoma of the urachus) for Diagnosis Please, Case 44. The names and locations of the individuals, as submitted, are as follows:
- Pablo Jose Abbona, MD, Mar del Plata, Argentina
- Hisashi Abe, Suita-city, Osaka, Japan
- Gholamali Afshang, MD, Tinley Park, Ill
- Albert J. Alter, Madison, Wis
- Guenther Antes, MD, Kempten, Germany
- Roger L. Antonelli, MD, Dayton, Ohio
- Dean Baird, MD, Arlington, Va
- Edward L. Baker, MD, San Francisco, Calif
- Ken Baliga, Rockford, Ill
- Dvora Balsam, MD, Bellmore, NY
- Viren Balsara, MD, Woodlands, Tex
- Marc P. Banner, Philadelphia, Pa
- Amita Bhandari, South San Francisco, Calif
- Dr Anu Bhandari, Jaipur, India
- Jeffrey Black, Lafayette, Calif
- Marcelo Bordalo Rodrigues, São Paulo, Brazil
- Adrian Brady, Cork, Ireland
- Eric L. Bressler, MD, Minnetonka, Minn
- Douglas Brown, MD, Virginia Beach, Va
- Andrea Bruscagnin, MD, Venezia, Italy
- Michael P. Buetow, MD, Okemos, Mich
- Martín Campi, MD, Mar del Plata, Argentina
- Dr Tirso Cascajares Murillo, Los Mochis, Sinaloa, Mexico
- Nelson M. G. Caserta, MD, Campinas, São Paulo, Brazil
- Paul J. Chang, MD, Pittsburgh, Pa
- Bharath Chinta, Pontiac, Mich
- Pablo Cikman, MD, Cordoba, Argentina
- Jay Colby, MD, Shrewsbury, Mass
- James W. Cole, MD, Cincinnati, Ohio
- Y. S. Cordoliani, MD, Paris, France
- Flavio Corti, MD, Mar del Plata, Argentina
- Dominique Crolla, MD, Roeselare, Belgium
- Marcio Curvelo, MD, Bellmore, NY
- Ajay Dabra, Chandigarh, India
- Rafal Darecki, MD, Koscierzyna, Poland
- M. G. de Baets, MD, Lugano, Switzerland
- Alejandro de la Vega, MD, Buenos Aires, Argentina
- Manoel de Souza Rocha, MD, São Paulo, Brazil
- Kemal Demir, MD, Ataköy, Istanbul, Turkey
- Dr Estela Di Nella, Mar del Plata, Argentina
- Keith D. Epperson, MD, Milwaukee, Wis
- Laura Z. Fenton, MD, Denver, Colo
- Gabriel C. Fernández Pérez, Vigo, Spain
- Francis Flaherty, MD, Ridgefield, Conn
- Arie Franco, MD, PhD, Livingston, NJ
- Milton R. Fuentealba, MD, General Roca, Río Negro, Argentina
- Akira Fujikawa, Tokyo, Japan
- Mitsuhiro Furusawa, MD, Takatsuka, Yame, Japan
- Roberto García Figueiras, MD, Santiago de Compostela, Spain
- Martin Garcia Perez, Almeria, Spain
- Douglas Gardner, MD, Windsor, Ontario, Canada
- Ronald B. J. Glass, MD, New York, NY
- Mark Goldshein, MD, Andover, Mass
- Bhaskar Golla, Kingston, Pa
- Herbert F. Gramm, Boston, Mass
- John Grizzard, MD, Midlothian, Va
- Yukihiro Hama, Tokorozawa, Japan
- Ian Hammond, MD, Ottawa, Ontario, Canada
- April Hatterick, Burlington, Vt
- Rufus W. Head, MD, North Bridgton, Me
- Howard T. Heller, MD, Garden City, NY
- Dr Alberto Iaia, Wilmington, Del
- Bill Jackson, Tacoma, Wash
- Daniel Jacobson, MD, Rochester, NY
- Dr Anupam Jhobta, Chandigarh, India
- Kenji Kachi, MD, Tokyo, Japan
- Hirotsugu Kado, Fukui, Japan
- Ercan Karaarslan, Istanbul, Turkey
- Musturay Karcaaltincaba, MD, Milwaukee, Wis
- Masako Kataoka, MD, Kyoto, Japan
- Douglas S. Katz, MD, Mineola, NY
- Hyung Seok Kim, Seoul, Korea
- Mitchell A. Klein, MD, Milwaukee, Wis
- Steven A. Klein, MD, Worcester, Mass
- Arlene Klink, MD, Irvine, Calif
- Thorsten L. Krebs, MD, Danbury, Conn
- Glenn Krinsky, New York, NY
- Jeffrey Kuo, Rockville, Md
- Dong L. Kwak, MD, Roanoke, Va
- Stefanos Lachanis, MD, Athens, Greece
- Mario A. Laguna, West Allis, Wis
- Wen-jeng Lee, Taipei, Taiwan
- Mark E. Lockhart, Birmingham, Ala
- Dr Elira Lomban, Cipolletti, Río Negro, Argentina
- Antonio J. Madureira, MD, Porto, Portugal
- Yoji Maetani, MD, Kyoto, Japan
- Tatsuya Ya Magen, Fukui City, Fukui, Japan
- Carlos Maia, Jr, São Paulo, Brazil
- N. B. S. Mani, MD, Chandigarh, India
- Dr Mirko Marra, Cipolletti, Río Negro, Argentina
- Javier Martinez, MD, Comodoro Rivadavia, Argentina
- Frank McKowne, Vancouver, Wash
- Dr Lucía Medina, Cipolletti, Río Negro, Argentina
- Dr Luis Mendez-Uriburu, Tucumán, Argentina
- Carolina Mendiondo, Mar del Plata, Argentina
- Edward Menges, Aptos, Calif
- Steve Meshkov, MD, Yardley, Pa
- Stephen F. Miller, MD, Toronto, Ontario, Canada
- Manabu Minami, MD, Tokyo, Japan
- Howard J. Mindell, MD, Burlington, Vt
- Hidetoshi Miyake, MD, Oita, Japan
- Dr Monica, Chandigarh, India
- Carlos J. Nassar, MD, Humacao, Puerto Rico
- Cristine Norwig Galvao, Barretos, São Paulo, Brazil
- James Okoh, Columbia, Md
- Sanford M. Ornstein, MD, Phoenix, Ariz
- David M. Panicek, MD, New York, NY
- Harish Panicker, Detroit, Mich
- Narendrakumar P. Patel, MD, Newburgh, NY
- Nicola Pelosi, MD, Palmanova, Italy
- Steven Perlmutter, MD, Mineola, NY
- Carlo L. E. Petralli, Bruderholz, Switzerland
- Jose Maria Pinto Varela, MD, Toledo, Spain
- John M. Plotke, Naperville, Ill
- R. Prashant, Chandigarh, India
- Shawn P. Quillin, MD, Charlotte, NC
- George A. Rabey, MD, Fresno, Calif
- M. R. Ramakrishnan, MD, Big Stone Gap, Va
- James Ravenel, MD, Charleston, SC
- Dr Ravinder, Chandigarh, India
- Enrique Remartinez Escobar, MD, Melilla, Spain
- Fernando Roithmann, Porto Alegre, RS, Brazil
- Natan Roithmann, Porto Alegre, Brazil
- Dr Saravanan, Chandigarh, India
- Pierre Sauvage, MD, Niamey, Niger
- Yildiray Savas, MD, Istanbul, Turkey
- Janet Scheraga, Tully, NY
- Dr Alejandro Schroeder, Cipolletti, Río Negro, Argentina
- Steven M. Schultz, MD, Fort Worth, Tex
- Anthony J. Scuderi, MD, Johnstown, Pa
- Dr Kanika Sekhri, Ahmedabad, India
- Matt Shapiro, MD, Lowell, Mass
- Taro Shimono, MD, Osaka, Japan
- Joseph E. Slawek III, MD, Moorestown, NJ
- Darrin S. Smith, MD, Tulare, Calif
- Kushaljit Singh Sodhi, MD, Chandigarh, India
- Uri Soimu, MD, Hadera, Israel
- James D. Sprinkle, Jr, MD, Fredericksburg, Va
- Brett Storm, Tallahassee, Fla
- Wing H. Tam, MD, Windsor, Ontario, Canada
- Akihiro Tanimoto, MD, Tokyo, Japan
- Douglas L. Teich, MD, Brookline, Mass
- Alejandro Tempra, MD, Mar del Plata, Argentina
- Dhurairaj Thiruvenkatasamy, Coimbatore, India
- Joseph Z. H. Toutounji, Beirut, Lebanon
- Gustavo A. Triana, Santa Fe de Bogotá, Colombia
- Herminia Tyminski Al-Saffar, MD, Manama, Bahrain
- Kai Vilanova Busquets, MD, Girona, Spain
- Raimo Virkki, MD, Turku, Finland
- Christopher Vittore, MD, Rockford, Ill
- Peter Waibel, MD, St Gallen, Switzerland
- Stan Wasilewski, MD, Skive, Denmark
- Jeff West, MD, Jacksonville, Fla
- Keith Wittenberg, MD, Saint Paul, Minn
- David J. Wright, MD, Lake Oswego, Ore
- Carlos Yarke, Mar del Plata, Argentina
- Stanko Yovichevich, MD, Sydney, New South Wales, Australia
- Joe Yut, Olathe, Kan
- Valentin Zambrana, MD, Mazatlán, Sinaloa, Mexico
- Jeffrey H. Zapolsky, Oshkosh, Wis
- Yu Zhang, Nagoya, Japan
TOP
HISTORY
IMAGING FINDINGS
