0022-534 7/86/1365-1086$02.00 /0 Vol. 136, November Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright© 1986 by The Williams & Wilkins Co.
METASTATIC SEMINOMA WITH REGRESSION OF TESTICULAR PRIMARY: ULTRASONOGRAPHIC DETECTION GEORGE W. GROSS,* THOMAS J. ROHNER, JR., JEFFREY S. LOMBARD AND CATHERINE S. ABRAMS From the Departments of Radiology, Urology and Pathology, Milton S. Hershey Medical Center, Hershey, Pennsylvania
We report a case of seminoma of the testis metastatic to the retroperitoneum. Biopsy of the retroperitoneal mass revealed anaplastic seminoma. No testicular mass could be palpated. Testicular ultrasonography showed a hypoechoic 3 X 2 cm. area in the left testis suggestive of a primary testicular tumor, most likely a seminoma., Histological evaluation of the resected testis revealed fibrous tissue but no definable tumor. Testicular ultrasonography is of proved value in the evaluation of palpable testicular masses and/or enlarged scrotal sacs, 1 • 2 as well as in the detection of occult testicular tumors in patients with metastatic testicular neoplasm but clinically normal testes. 3 - 7 Histological evaluation of the resected testicular lesion, as identified by ultrasonography, confirms the primary site within the testis, which typically:correlates well with metastatic disease when present. We could find only 1 previous report of metastatic testicular tumor associated with a clinically occult testicular lesion, which was identified by ultrasonography and in which no residual tumor cells were present on histological evaluation of the testis. 3 CASE REPORT
A 37-year-old white man presented with intermittent left anterior abdominal pain radiating to the left groin and flank 2 months in duration. There was no associated fever, chills, fatigue, dysuria or change in bowel habits. A moderately tender, nonmobile, 10 X 10 cm. mass was present in the left side of the mid abdomen. No testicular mass could be palpated. Urinalysis showed no hematuria. !'I-Human chorionic gonadotropin and afetoprotein levels were normal. Initial imaging with excretory urography and ultras0nography elsewhere had suggested a left renal mass. Abdominal computerized tomography (CT) at our hospital demonstrated a 9 X 9 X 10 cm. well circumscribed uncalcified retroperitoneal soft tissue mass anteromedial to but separate from the left kidney. The left upper collecting system was mildly obstructed by the mass. A chest CT was negative for metastatic disease. Angiography revealed the mass to be relatively avascular and separate from the left kidney. CT-guided needle biopsy of the mass demonstrated a malignant tumor (renal cell carcinoma versus sarcoma). Subsequently, en bloc resection of the left kidney and mass was performed. The mass was an anaplastic seminoma (fig. 1) and the kidney was uninvolved with tumor. Testicular ultrasonography was performed because of the nature of the retroperitoneal tumor. The right testis was normal but mild relative enlargement of the left testis was noted, which contained a 3 X 2 cm. hypoechoic zone, suggestive of seminoma (fig. 2). Subsequent left radical orchiectomy was performed. On cut section the testis showed normal residual testicular tissue peripherally, while the central testicular zone (corresponding to the hypoechoic area on ultrasonography) was replaced by white, firm, nonhemorrhagic tissue (fig. 3). Microscopically, the testicular parenchyma was replaced almost completely by relaAccepted for publication June 12, 1986. * Requests for reprints: Department of Radiology, Milton S. Hershey Medical Center, P. 0. Box 850, Hershey, Pennsylvania 17033.
tively acellular, loose to dense collagenous tissue with scattered plasma and mast cells, and entrapped remnants of seminiferous tubules (fig. 4). No tumor cells could be identified despite extensive examination. At 6-month followup abdominal CT revealed no evidence of residual or recurrent tumor, and a-fetoprotein and !'I-human chorionic gonadotropin levels as well as complete blood count were normal. Three adjuvant courses of chemotherapy, consisting of cis-platinum, vinblastine sulfate and bleomycin, have been started. DISCUSSION
Seminoma is the most common of the germ cell tumors arising in the testis. 8 These tumors typically consist of sheets of round epithelial cells with clear cytoplasm and large nuclei. 8 Fibrous septa infiltrated with lymphocytes course through the tumor. 8 Metastatic spread usually is via lymphatic channels to lumbar and mediastinal nodes. 8 Renal and ureteral displacement secondary to retroperitoneal adenopathy is common. 8 Anaplastic (poorly differentiated) seminoma, representing 5 to 15 per cent of all seminomas, has a propensity to early metastasis but carries a 5-year apparent cure rate of up to 80 per cent. 9 Ultrasonography can identify reliably a variety of testicular disorders, including tumors. 1 • 2 Seminoma of the testis may appear as a homogeneously hypoechoic zone, with sharply
FIG. 1. High power magnification of retroperitoneal tumor. Neoplasm consists of nests of loosely cohesive, pleomorphic cells with frequent mitotic figures. Fine fibrovascular septa containing numerous lymphocytes separate nests of tumor cells. Features are those of anaplastic seminoma. Reduced from X64.
1-AE'TASTATIC SEiv1IN0l\.1A VJI'1'H REGRBSSI()l,J OF TESTICTJLAR PREviARY
FIG. 4. Histological section of left testis corresponds to hypoechoic zone on testicular ultrasonography. Residual atrophic seminiferous tubules are surrounded by dense collagenous tissue. No neoplastic cells could be identified in testis. Reduced from X160.
FIG. 2. Longitudinal real-time ultrasound images of right (A) and left (B) testes. Echogenic pattern throughout right testis is normal. Left testis contains 3 X 2 cm. uniformly hypoechoic zone (arrows) suggestive of seminoma. Remainder of left testis is normal.
FIG. 3. Gross specimen of resected bivalved left testis. Epididymis is-at bottom right of photograph. Testicular parenchyma is replaced by firm, white fibrous tissue (arrows).
demarcated borders,1 homogeneous but poorly marginated hypoechoic masses 2 or inhomogeneous, poorly marginated masses with focal areas of increased echogenicity. 2 In contrast, embryonal cell tumors typically demonstrate a mixed or complex pattern, with poorly defined margins, cystic areas and acoustic shadowing. 1 Reliable differentiation between seminoma and embryonal cell carcinoma based on ultrasonographic appearance alone usually is not possible. 2 In most patients with testicular seminoma, either localized to the testis or associated with metastatic disease, a palpable testicular mass is present.(; Infrequently, however, a metastatic testicular neoplasm has no associated palpable testicular le-
sion, 3- 7 • 10 a situation in which ultrasonography may identify a clinically occult intratesticular primary. Histological evaluation of the resected testis typically demonstrates a neoplasm, which usually is a seminoma. 4 - 7 A review of the literature revealed only 1 previous report of a patient with metastatic seminoma, clinically normal testes, an intratesticular hypoechoic mass identified by ultrasonography and no tumor on histological evaluation of the resected testis. 3 Our patient had similar clinical and ultrasonographic findings. Levels of JJ-human chorionic gonadotropin and a-fetoprotein were normal in both patients. The resected testis in our patient demonstrated a large zone of fibrous tissue with focal edema rather than necrosis as in the previous report. 3 When an extragonadal germ cell tumor is not associated with an intratesticular tumor, the question of a primary extragonadal lesion arises. There are 2 theories that support the concept of primary extragonadal germ cell tumors: 1) primordial germ cell rests owing to incomplete migration from the urogenital ridge or entodermal yolk sac and 2) tumor cell origination from totipotential cells that extraneously attach to other organs. 3 Although uncommon, there are well documented cases of mature teratoma, malignant teratoma, embryonai carcinoma, choriocarcinoma and seminoma that occur as primary neoplasms of the anterior mediastinum, retroperitoneum, presacral area and pineal region.n However, primary testicular neoplasms can shovv local regression associated with progressing metastatic disease. 3 · 12 ·rn Unilateral fibrous scarring within a testis associated with a metastatic germ cell tumor (including seminoma) has been documented and is attributed to necrosis of nuclear chromatin caused by ischemia and an accelerated tumor metabolic rate.a, 12 This would appear to explain the differing retroperitoneal and testicular histologies in our patient. We would speculate that in time the zone of fibrosis in the testis would have regressed to a much smaller lesion microscopically identifiable but not definable by testicular ultrasonography. Based on the clinical, ultrasonographic and pathological findings in our patient, should a clinically palpable and/or ultrasonographically definable testicular lesion prove on histological evaluation to be free of neoplastic tissue, regression of a primary testicular seminoma should be considered and evaluation for possible metastatic tumor may be appropriate. Furthermore, it would seem appropriate to recommend testicular ultrasonography in all male patients presenting with retroperitoneal masses, regardless of physical findings on scrotal examination. Important patient management decisions may be altered by the ultrasonographic findings. In our patient one would still have
GROSS AND ASSOCIATES
had to biopsy the retroperitoneal mass to obtain a correct tissue diagnosis but a more conservative retroperitoneal procedure might have been done had we been aware of the testicular ultrasonographic and histological findings. REFERENCES 1. Nachtsheim, D. A., Scheible, F. W. and Gosink, B.: Ultrasonography of testis tumors. J. Urol., 129: 978, 1983. 2. Carroll, B. A. and Gross, D. M.: High-frequency scrotal sonography. Amer. ,J. Roentgen., 140: 511, 1983. 3. Kirschling, R. J., Kvols, L. K., Charboneau, J. W., Grantham, J. G. and Zincke, H.: High-resolution ultrasonographic and pathologic abnormalities of germ cell tumors in patients with clinically normal testes. Mayo Clin. Proc., 58: 648, 1983. 4. Peterson, L. J., Catalana, W. J. and Koehler, R. E.: Ultrasonic localization of a non-palpable testis tumor. J. Urol., 122: 843, 1979. 5. Bockrath, J.M., Schaeffer, A. J., Kies, M. S. and Neiman, H. L.: Ultrasound identification of impalpable testicle tumor. J. Urol., 130: 355, 1983. 6. Moudy, P. C. and Makhija, J. S.: Ultrasonic demonstration of a non-palpable testicular tumor. J. Clin. Ultrasound, 11: 54, 1983.
7. Glazer, H. S., Lee, J. K. T., Melson, G. L. and McClennan, B. L.: Sonographic detection of occult testicular neoplasms. Amer. J. Roentgen., 138: 673, 1982. 8. Smith, D. R.: Tumors of the genitourinary tract. In: General Urology, 7th ed. Los Altos, California: Lange Medical Publications, chapt. 17, p. 287, 1972. 9. Cockburn, A.G., Vugrin, D., Batata, M., Hajdu, S. and Whitmore, W. F.: Poorly differentiated (anaplastic) seminoma of the testis. Cancer, 53: 1991, 1984. 10. Bliss, W. R. and Barnett, W. H.: Retroperitoneal seminoma (germinoma) without evidence of testicular involvement. Amer. J. Surg., 120: 363, 1970. 11. Luna, M. A.: Extragonadal germ cell tumors. In: Testicular Tumors, 2nd ed. Edited by D. E. Johnson. Flushing, New York: Medical Examination Publishing Co., Inc., chapt. 14, pp. 261265, 1976. 12. Azzopardi, J. G., Mostofi, F. K. and Theiss, E. A.: Lesions of testes observed in certain patients with widespread choriocarcinoma and related tumors. The significance and genesis of hematoxylinstaining bodies in the human testis. Amer. J. Path., 38: 207, 1961. 13. Friedman, N. B.: Comparative morphogenesis of extragenital and gonadal teratoid tumors. Cancer, 4: 265, 1951.