Tumors of the Testis: A Report on 922 Cases12

TUMORS OF THE TESTIS: A REPORT ON 922 CASES 1,2 NATHAN B. FRIEDMAN, MAJOR, MC, AUS AND ROBERT A. MOORE, RESIDENT CONSULTANT From the Army Institute of Pathology, Washington, D. C. and the Department of Pathology, · Washington University School of Medicine, St. Louis, Missouri

Study of 922 tumors of the testis collected at the Army Institute of Pathology between October 1940 and May 1946 established that 96 per cent of such new growths can be classified as seminoma, embryonal carcinoma, teratoma or teratocarcinoma. One per cent were interstitial cell tumors and 3 per cent were rare or unclassifiable varieties. Seminomas and embryonal carcinomas are distinct tumors which differ not only in fundamental cell type but in biologic behavior and prognosis. Chorioepitheliomas are considered a subvariety of embryonal carcinomas. The term. teratocarcinoma is applied to those tumors which show both differentiated tera~ toid structures and malignant elements and are thought to result from teratoid differentiation in embryonal carcinomas. Moncellular testicular neoplasms do not ordinarily originate from preexisting teratomas. Virtually all embryonal carcinomas metastasize as monocellular embryonal carcinomas, but choriomatous characteristics may be evident in the metastases of embryonal carcinomas or teratocarcinomas even when they are not manife:;;t in the primary tumors. Roughly half of the teratoid neoplasms which metastasize give rise to growths with teratocarcinomatous structures and half to pure embryonal carcinomas. Immediate prognosis is bad for embryonal carcinomas and chorioepitheliomas and poor for teratocarcinomas and adult teratomas, which should be regarded as matured teratocarcinomas. Seminomas, in comparison with the other testicular tumors, have a good immediate prognosis. The architecture of testicular tissue is not reproduced in seminomas, and the neoplastic cells do not resemble spermatogonia. Seminomas are probably tumors of primordial germ cells and should be called germinomas. Embryonal carcinomas and teratoid tumors, which are composed of evolving and differentiating somatic and trophoblastic tissues, are neoplastic expressions of the unlimited potencies of embryonic cells. They are dynamic, not static; appreciation of the fact that their structural components keep changing makes it possible to explain the complex intermingled patterns of some neoplasms. The new growths of the male gonad appear exceptional in that they do not reproduce testicular tissue while most other neoplasms reflect the architecture of the tissue in which they originate. Tumors of the testis express, in distorted fashion, the latent unlimited potencies of the embryonic germ cells from which they arise, while other tumors can make manifest only the limited potencies of their somatic cells of origin. It is important to determine whether a common oncologic principle underlies all new growths or whether the testicular neoplasms and other teratoid growths are truly unique. 1 Read

at annual meeting, American Urological Association, Cincinnati, 0., July 25, 1946: This report in full was one of the Contributions to Pathology in honor of Colonel J.E. Ash, published as a special number of the Military Surgeon, November, 1946. For this reason only an abstract is being printed in the Journal of Urology. EDITORS 2

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