DOI: 10.1148/radiol.2301021059
(Radiology 2004;231:388-392.)
Case 70: Seminoma in an Undescended Testis1
Paula J. Woodward, MD
1 From the Department of Radiologic Pathology, Armed Forces Institute of Pathology, Bldg 54, Room M-121, Washington, DC 20306-6000. Received August 22, 2002; revision requested October 24; revision received December 19; accepted February 7, 2003. Address correspondence to the author (e-mail: woodwardp@afip.osd.mil).
Index terms: Diagnosis Please • Seminoma, 847.329 • Testis, neoplasms, 847.329 • Testis, undescended, 847.1477
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HISTORY
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A 47-year-old man presented with a 1-month history of progressive abdominal pain. He was in good health until this time, and he had not previously undergone surgery. A right lower-quadrant mass was noted at physical examination. A computed tomographic (CT) examination was performed.
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IMAGING FINDINGS
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The dominant finding and the likely cause of abdominal pain is a large mass in the right side of the patient’s body. CT scans show a predominantly soft-tissue attenuation mass, with areas of peripheral enhancement located superiorly (Figure, part b) and areas of necrosis located inferiorly (Figure, part c). There is no evidence of calcification or fat within the mass. It is exerting mass effect, with medial displacement of bowel loops and compression of the inferior vena cava (Figure, part b). No adenopathy is present.
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Figure a. Transverse CT scans obtained after administration of intravenous and oral contrast material. (a) CT scan obtained through the level of the kidneys shows bowel within the right renal fossa (arrow) because the right kidney is absent. Note the small amount of free fluid. (b, c) Large right-sided soft-tissue attenuation mass with some areas of peripheral enhancement superiorly (white arrow in b) and necrosis inferiorly (white arrow in c). Note compressed inferior vena cava (black arrow). (d) CT scan obtained through the bladder base shows a normal left seminal vesicle (arrow) with absence of the right seminal vesicle. (e) Absent right spermatic cord and normal left spermatic cord (arrow).
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Figure b. Transverse CT scans obtained after administration of intravenous and oral contrast material. (a) CT scan obtained through the level of the kidneys shows bowel within the right renal fossa (arrow) because the right kidney is absent. Note the small amount of free fluid. (b, c) Large right-sided soft-tissue attenuation mass with some areas of peripheral enhancement superiorly (white arrow in b) and necrosis inferiorly (white arrow in c). Note compressed inferior vena cava (black arrow). (d) CT scan obtained through the bladder base shows a normal left seminal vesicle (arrow) with absence of the right seminal vesicle. (e) Absent right spermatic cord and normal left spermatic cord (arrow).
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Figure c. Transverse CT scans obtained after administration of intravenous and oral contrast material. (a) CT scan obtained through the level of the kidneys shows bowel within the right renal fossa (arrow) because the right kidney is absent. Note the small amount of free fluid. (b, c) Large right-sided soft-tissue attenuation mass with some areas of peripheral enhancement superiorly (white arrow in b) and necrosis inferiorly (white arrow in c). Note compressed inferior vena cava (black arrow). (d) CT scan obtained through the bladder base shows a normal left seminal vesicle (arrow) with absence of the right seminal vesicle. (e) Absent right spermatic cord and normal left spermatic cord (arrow).
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Figure d. Transverse CT scans obtained after administration of intravenous and oral contrast material. (a) CT scan obtained through the level of the kidneys shows bowel within the right renal fossa (arrow) because the right kidney is absent. Note the small amount of free fluid. (b, c) Large right-sided soft-tissue attenuation mass with some areas of peripheral enhancement superiorly (white arrow in b) and necrosis inferiorly (white arrow in c). Note compressed inferior vena cava (black arrow). (d) CT scan obtained through the bladder base shows a normal left seminal vesicle (arrow) with absence of the right seminal vesicle. (e) Absent right spermatic cord and normal left spermatic cord (arrow).
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Figure e. Transverse CT scans obtained after administration of intravenous and oral contrast material. (a) CT scan obtained through the level of the kidneys shows bowel within the right renal fossa (arrow) because the right kidney is absent. Note the small amount of free fluid. (b, c) Large right-sided soft-tissue attenuation mass with some areas of peripheral enhancement superiorly (white arrow in b) and necrosis inferiorly (white arrow in c). Note compressed inferior vena cava (black arrow). (d) CT scan obtained through the bladder base shows a normal left seminal vesicle (arrow) with absence of the right seminal vesicle. (e) Absent right spermatic cord and normal left spermatic cord (arrow).
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No kidney can be identified in the right renal fossa (Figure, part a). There is congenital absence of the right seminal vesicle (Figure, part d). In addition, the right spermatic cord is absent, which indicates either incomplete descent or agenesis of the right testis.
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DISCUSSION
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The differential diagnoses for a retroperitoneal mass are many and include both benign and malignant entities. Benign lesions include retroperitoneal fibrosis, which on occasion can make bulky masses, and extramedullary hematopoiesis. The large size and focal nature of this mass makes these diagnoses unlikely. Lymphoma and metastatic adenopathy are two of the most common soft-tissue masses seen in the retroperitoneum and should be considered. In addition, primary tumors of either neurogenic or mesenchymal origin should be included in the differential diagnoses. These tumors most commonly include paraganglioma (patients are usually symptomatic), liposarcoma (visible fat may not be depicted with CT in aggressive high-grade tumors), leiomyosarcoma, and malignant fibrous histiocytoma. There is a great deal of overlap in the imaging findings of many of these masses.
None of the above diagnoses would account for the other findings, which include absence of the right spermatic cord, kidney, and seminal vesicle. One potential explanation would be a tumor within an ectopic kidney associated with agenesis of the right seminal vesicle and testis. None of the images, however, show normal renal parenchyma. Even with a very large or infiltrating renal tumor, some normal parenchyma can usually be identified. Given the lack of any identifiable kidney on the right side, it is more likely congenitally absent than ectopic. The findings of an absent right spermatic cord, kidney, and seminal vesicle—in combination with the soft-tissue mass located along the path of testicular descent—make the most likely diagnosis tumor within an undescended testis.
Cryptorchidism results from the abnormal formation and descent of the testes. The testes form from genital ridges, which lie on both sides of the midline and extend from T6 through S2 vertebrae in the developing embryo. Between the 7th and 12th weeks of gestation, the testes contract and become more ovoid as they begin their descent into the pelvis. They remain near the deep inguinal ring until the 7th month of gestation, when they begin their descent through the inguinal canal into twin scrotal sacs. Passage through the inguinal canal is aided by both the processus vaginalis and the shortening of the gubernaculum. The processus vaginalis is a sock-like evagination of peritoneum that elongates caudally through the abdominal wall into the scrotum and creates a path for the descending testis. The gubernaculum is a ligamentous cord that extends from the testis to the scrotum. The testes remain retroperitoneal throughout their descent but are intimately associated with the posterior wall of the processus vaginalis (1,2).
At approximately 8 weeks gestational age, the Leydig cells begin to secrete testosterone, thus inducing this process. In addition, because of this hormonal influence, the mesonephric (wolffian) ducts differentiate into the epididymis, vas deferens, seminal vesicles, and ejaculatory ducts. Concurrently, the Sertoli cells secrete müllerian inhibiting factor, which results in regression of the paramesonephric (müllerian) ducts. A vestigial remnant of this system may persist as the appendix testis (1,2).
Cryptorchidism is present in approximately 6% of full-term neonates and approximately 0.8% of infants at 1 year of age. It can be bilateral in 10% of patients (3,4). Because of its association with other urinary tract abnormalities, cryptorchidism is thought to be one manifestation of a generalized defect in genitourinary embryogenesis. Other associated malformations include renal agenesis or ectopias, ureteral duplications, seminal vesicle agenesis or cysts, and hypospadias (5–9).
Cryptorchidism is also associated with infertility and is a well-recognized risk factor for testicular carcinoma. Approximately 90% of these tumors are seminomas, especially those that occur in the abdominally located testis. Although the overall incidence of cryptorchidism is low (<1%), a history of an undescended testis is present in 3.5%–14.5% of patients with testicular tumors (9). The pathophysiology of malignant transformation in these testes is not completely understood. One hypothesis is that cryptorchidism is not merely incomplete descent of the testis, but that it reflects a generalized defect in embryogenesis and results in bilateral dysgenetic gonads.
An embryologic defect in testicular formation is supported by several important clinical observations. The most compelling of these is that risk for testicular carcinoma is not limited to the undescended testis but extends to the contralateral testis, even if it is normally descended. Thus, the increased risk of carcinoma cannot be attributed to local environmental factors, such as increased temperature in the abdomen versus the scrotum. While it is true that the risk of carcinoma increases with the degree of ectopy (intraabdominal testes are at greater risk than those in the inguinal canal), this also supports the theory if it is assumed that the greatest degree of ectopy reflects the greatest perturbation of embryogenesis. The defective embryogenesis hypothesis is further supported by the observation that orchiopexy, even at an early age, does not appreciably decrease the risk of developing a tumor (9).
The majority of cryptorchid testes lie distal to the external inguinal ring and are palpable. Nonpalpable testes are most commonly located within the inguinal canal, but they can be located anywhere along the path of descent from the abdomen. Testicular agenesis has been reported to be present in 15%–63% of patients with a nonpalpable testis (4,10). The distinction between agenesis and maldescent is critical, as orchiopexy should be performed in all patients with undescended testes. This is usually performed between 1 and 2 years of age. If performed later, the testis will have undergone marked morphologic change, with fibrosis and collagen deposition adversely affecting spermatogenesis and fertility (11). While orchiopexy improves fertility, it does not alter the risk of developing a carcinoma. Because of this increased risk, testicular biopsies have been recommended to aid in the identification of intratubular germ cell neoplasia of the unclassified type (carcinoma in situ). If the biopsy results are positive for intratubular neoplasia, the patient has a 50% chance of developing invasive carcinoma; however, if the biopsy results are negative for intratubular neoplasia, the patient does not have an increased risk for developing carcinoma. A single postpubertal biopsy of each testis at 18–20 years of age is suggested and appears to be adequate for identification of high-risk patients (9,12).
Imaging can be helpful in localizing a nonpalpable testis. An undescended testis will appear hypoechoic with ultrasonography (US), and a mediastinum testis should be identified for confident diagnosis. There are many potential pitfalls, including possible confusion with lymph nodes and the pars infravaginalis gubernaculi, which is a bulbous termination of the gubernaculum (4,13). More importantly, agenesis cannot be discriminated from atrophy with US (3,4). CT also lacks the specificity and sensitivity that are needed to diagnose agenesis. Magnetic resonance (MR) imaging has the advantage of improved soft-tissue contrast, but reports have varied as to its usefulness (11,14). The results of a study by Lam et al (15) showed that gadolinium-enhanced MR venography performed in conjunction with routine pelvic MR imaging increased sensitivity for differentiation of agenesis from ectopia. Because surgery is obviated only if the testis can be proved to be absent, many urologists feel that the treatment of choice is laparoscopy, which can be both diagnostic and therapeutic (16,17). Some cases, however, will still require open inguinal exploration and abdominal laporotomy (18). Preoperative imaging may help in surgical planning in these patients.
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FOOTNOTES
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The opinions and assertions contained herein are the private views of the author and are not to be construed as official nor as representing the views of the Department of the Defense.
Part one of this case appeared 4 months previously and may contain larger images.
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REFERENCES
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- Larsen WJ. Human embryology New York, NY: Churchill Livingstone, 1993; 235-280.
- Moore KL, Persaud TV. The developing human: clinically oriented embryology 5th ed. Philadelphia, Pa: Saunders, 1993; 281-303.
- Friedland GW, Chang P. The role of imaging in the management of the impalpable undescended testis. AJR Am J Roentgenol 1988; 151:1107-1111.[Free Full Text]
- Frush DP, Sheldon CA. Diagnostic imaging for pediatric scrotal disorders. RadioGraphics 1998; 18:969-985.[Abstract]
- Pappis CH, Argianas SA, Bousgas D, Athanasiades E. Unsuspected urological anomalies in asymptomatic cryptorchid boys. Pediatr Radiol 1988; 18:51-53.[CrossRef][Medline]
- Schlegel PN, Shin D, Goldstein M. Urogenital anomalies in men with congenital absence of the vas deferens. J Urol 1996; 155:1644-1648.[CrossRef][Medline]
- Cortes D. Cryptorchidism: aspects of pathogenesis, histology and treatment. Scand J Urol Nephrol Suppl 1998; 196:1-54.[CrossRef][Medline]
- Flageat J, Vicens JL, Metges PJ. Seminoma on ectopic testis associated with renal agenesis. J Radiol 1982; 63:763-765.[Medline]
- Ulbright TM, Amin MB, Young RH. Miscellaneous primary tumors of the testis, adnexa, and spermatic cord. In: Rosai J, Sobin LH, eds. Atlas of Tumor Pathology, fasc 25, ser 3. Washington, DC: Armed Forces Institute of Pathology, 1999; 235-366.
- Weiss RM, Seashore JH. Laparoscopy in the management of the nonpalpable testis. J Urol 1987; 138:382-384.[Medline]
- Kier R, McCarthy S, Rosenfield AT, Rosenfield NS, Rapoport S, Weiss RM. Nonpalpable testes in young boys: evaluation with MR imaging. Radiology 1988; 169:429-433.[Abstract/Free Full Text]
- Giwercman A, Bruun E, Frimodt-Moller C, Skakkebaek NE. Prevalence of carcinoma in situ and other histopathological abnormalities in testes of men with a history of cryptorchidism. J Urol 1989; 142:998-1002.
- Rosenfield AT, Blair DN, McCarthy S, Glickman MG, Rosenfield NS, Weiss R. Society of Uroradiology Award paper: the pars infravaginalis gubernaculi—importance in the identification of the undescended testis. AJR Am J Roentgenol 1989; 153:775-778.[Abstract/Free Full Text]
- Fritzsche PJ, Hricak H, Kogan BA, Winkler ML, Tanagho EA. Undescended testis: value of MR imaging. Radiology 1987; 164:169-173.[Abstract/Free Full Text]
- Lam WW, Tam PK, Ai VH, Chan KL, Chan FL, Leong L. Using gadolinium-infusion MR venography to show the impalpable testis in pediatric patients. AJR Am J Roentgenol 2001; 176:1221-1226.[Abstract/Free Full Text]
- Holcomb GW, III, Brock JW, III, Neblett WW, III, Pietsch JB, Morgan WM, III. Laparoscopy for the nonpalpable testis. Am Surg 1994; 60:143-147.[Medline]
- Vaysse P. Laparoscopy and impalpable testis: a prospective multicentric study—232 cases. GECI. Groupe d’Etude en Coeliochirurgie Infantile. Eur J Pediatr Surg 1994; 4:329-332.
- Wright JE. Impalpable testes: a review of 100 boys. J Pediatr Surg 1986; 21:151-153.[Medline]
Congratulations to the 142 individuals who submitted the most likely diagnosis (seminoma in an undescended testis) for Diagnosis Please, Case 70. The names and locations of the individuals, as submitted, are as follows:
- Gholamali Afshang, MD, Tinley Park, Ill
- Dr Jorge Ahualli, Tucuman, Argentina
- Oguz Akin, MD, New York, NY
- Priscilla Alexander, MD, Portland, Ore
- Canan Altay, MD, Izmir, Turkey
- Sedat Altay, MD, Inciralt
, Turkey
- Antonio Aparcero, Sevilla, Spain
- Dean Baird, MD, Arlington, Va
- Ken Baliga, Rockford, Ill
- Dvorah Balsam, MD, East Meadow, NY
- Rich Benedikt, MD, San Antonio, Tex
- Aldo Benjamim Rodrigues Barbosa, São José do Rio Preto, Brazil
- Lawrence N. Bennett, MD, Olympia, Wash
- Tom Berg, MD, Iowa City, Iowa
- Debra M. Berger, MD, New York, NY
- Grazia Bitti, Cagliari, Italy
- Roberto Blasbalg, São Paulo, Brazil
- Amy Bokal, MD, Tulsa, Okla
- Ronald N. Boyle, MD, La Plata, Md
- Dorthe S. Brandt, Leesburg, Va
- Eric L. Bressler, MD, Minnetonka, Minn
- Michael P. Buetow, MD, Okemos, Mich
- Peter Buetow, Bellingham, Wash
- Brian J. Burke, Manhasset, NY
- Julie G. Champine, MD, Dallas, Tex
- Michael H. Childress, MD, Silver Spring, Md
- Royce A. Chrys, Castro Valley, Calif
- James W. Cole, MD, Cincinnati, Ohio
- Jesse Cole, MD, Butte, Mont
- Y.-S. Cordoliani, MD, Paris, France
- David A. Cory, MD, South Bend, Ind
- Major Paul Cunningham, MD, Landstuhl, Germany
- Marc G. de Baets, MD, Lugano, Switzerland
- Peter C. De Baets, MD, Sijsele, Belgium
- Wagner Diniz de Paula, MD, Brasilia, Brazil
- J. F. K. de Villiers, Gisborne, New Zealand
- Mustafa Kemal Demir, MD, Istanbul, Turkey
- Christopher Dorvault, MD, Auburn, Ala
- Shella Farooki, Dublin, Ohio
- G. Peter Feola, MD, Salt Lake City, Utah
- Gabriel C. Fernández Pérez, Vigo, Spain
- Francis Flaherty, MD, Ridgefield, Conn
- Jonathan Foss, Bloomington, Ill
- Akira Fujikawa, Tokyo, Japan
- Ann S. Fulcher, MD, Richmond, Va
- Cristine Norwig Galvao, Barretos, Brazil
- Roberto García Figueiras, MD, Santiago de Compostela, Spain
- Ted Glass, MD, Jackson, Miss
- Mark Goldshein, MD, Andover, Mass
- Alvaro Gomez Naar, Salta, Argentina
- Philip Goodman, MD, Binghamton, NY
- John Grizzard, MD, Midlothian, Va
- Flavius Guglielmo, MD, Basking Ridge, NJ
- Yong H. Hahn, MD, Manhasset, NY
- Ferris M. Hall, MD, Boston, Mass
- David Harrison, MD, Cambridge, Mass
- Yasuhiro Hata, Osaka, Japan
- Marla Hersh, Tampa, Fla
- Thomas C. Hoffer, MD, El Paso, Tex
- Francois Humbert, MD, St Chamond, France
- Alberto Iaia, MD, Wilmington, Del
- Waleed Ibrahim, MD, Chapel Hill, NC
- Vladislav Jankulov, MD, Dearborn, Mich
- Kartik Jhaveri, Toronto, Ontario, Canada
- Mary Ann Johnson, MD, FRCPC, Edmonton, Alberta, Canada
- Masako Kataoka, Cambridge, UK
- Nurettin Katranci, MD, Antalya, Turkey
- Clifford T. Katz, MD, Baltimore, Md
- Korosh Khalili, Toronto, Ontario, Canada
- Takuji Kiryu, MD, Gifu, Japan
- Mitchell A. Klein, MD, Milwaukee, Wis
- Steven A. Klein, MD, Shrewsbury, Mass
- Ercan Kocakoc, MD, Elazig, Turkey
- Tasvinder Kour, MBBS, Chandigarh, India
- Jeffrey Lang, MD, New York, NY
- Margaret H. Lee, MD, Los Angeles, Calif
- John T. Lim, MD, Newport Coast, Calif
- David A. Lisle, Brisbane, Australia
- Charles Liu, MD, San Diego, Calif
- Dr Roussel Luc, Sijsele, Belgium
- Jason Lynn, MD, Columbia, SC
- Antonio J. Madureira, MD, Porto, Portugal
- Stephen Manghisi, MD, Closter, NJ
- John A. Mattingly, MD, Belleville, Ill
- John McIntyre, MD, San Francisco, Calif
- Frank McKowne, MD, Vancouver, Wash
- Luis Mendez-Uriburu, MD, Tucuman, Argentina
- Ur Metser, MD, Tel-Aviv, Israel
- Harlan D. Meyer, MD, Bexley, Ohio
- Mitchell A. Miller, MD, Hoboken, NJ
- Manabu Minami, MD, Tokyo, Japan
- Sankar Ranjan Mondal, MD, Nassau, Bahamas
- Dr Moataz Montasser, Alexandria, Egypt
- John R. Mootz, MD, Elmira, NY
- Annamalai Muthiah, Jr, MD, Charlottesville, Va
- Tetsuro Nakahara, Shiga, Japan
- Tetsuo Nakayama, MD, Osaka, Japan
- Michael Neuman, Portland, Ore
- Tuan D. Nguyen, MD, Voss, Norway
- Chuck Nicolette, Odessa, Tex
- Kourosh Nourisamie, MD, Costa Mesa, Calif
- Mike O’Loughlin, MD, West Hartford, Conn
- Sanford M. Ornstein, MD, Phoenix, Ariz
- Ann Owen, MD, Murfreesboro, Tenn
- David M. Panicek, MD, New York, NY
- Narendrakumar P. Patel, MD, Newburgh, NY
- Mario P. Pliego, MD, Bloomington, Minn
- Shawn P. Quillin, MD, Charlotte, NC
- Lorenz (Larry) Ramseyer, MD, Enid, Okla
- Enrique Remartinez Escobar, MD, Melilla, Spain
- Luiz Antonio Rossi, MD, São Paulo, Brazil
- N. Saravanan, MD, Chandigarh, India
- Stephen I. Schabel, MD, Charleston, SC
- Janet Scheraga, Syracuse, NY
- Dr Thomas Schmidhuber, Villach, Austria
- Steven M. Schultz, MD, Fort Worth, Tex
- Gerald Scidmore, MD, Corona del Mar, Calif
- Anthony J. Scuderi, MD, Johnstown, Pa
- Mustafa Secil, MD, Izmir, Turkey
- Taro Shimono, MD, Osaka, Japan
- Ali Shirkhoda, MD, Royal Oak, Mich
- Grady Shue, Heidelberg, Germany
- Michael K. Silberman, MD, Durham, NC
- S. Horatio Slawson, MD, Peoria, Ill
- David F. Sobel, MD, La Jolla, Calif
- James D. Sprinkle, Jr, MD, Spotsylvania, Va
- John M. Stewart, Caribou, Me
- Kouichi Sugiyama, Hamamatsu, Japan
- Denis M. Tack, MD, Mons, Belgium
- Norio Takahashi, Fukui, Japan
- Satoru Takahashi, Osaka, Japan
- Eugene Tong, MD, Austin, Tex
- Hiroyuki Ueda, Kyoto, Japan
- Kai Vilanova Busquets, Girona, Spain
- Christopher Vittore, MD, Rockford, Ill
- Jeff West, MD, Jacksonville, Fla
- Tatsuya Yamamoto, Obama, Japan
- Michio Yamasaki, Shiga, Japan
- Satoru Yoshida, MD, Muroran City, Japan
- Joe Yut, Olathe, Kan
- Jeffrey H. Zapolsky, Oshkosh, Wis
- Dahua Zhou, MD, East Meadow, NY
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HISTORY
IMAGING FINDINGS
