Yolk sac tumor associated with seminoma of the testis in adults

The yolk sac tumor: reflections on a remarkable neoplasm and two of the many intrigued by it-Gunnar Teilum and Aleksander Talerman-and the bond it formed between them

One of the most remarkable of human neoplasms, the yolk sac tumor, is reviewed, emphasizing its histologic diversity and differential diagnosis, occurrence at many sites, and the shared passion for this unique neoplasm of Dr Gunnar Teilum (who deserves almost all credit for delineation of the nature of the tumor and its features) and Dr Aleksander Talerman (who made his own contribution to our knowledge of it) and the friendship it helped forge between these 2 distinguished pathologists. In a unique series of articles, beginning in the early 1940s, Teilum delineated the distinctive features of the neoplasm and recognized that it was 1 of 2 initially included as "mesonephroma ovarii" by Dr Walter Schiller in 1939 (the second we now know as clear cell carcinoma). Teilum named the tumor "endodermal sinus tumor" because it came to his attention that papillary formations common in the yolk sac tumor resembled the endodermal sinuses of the rat placenta. He focused on the histogenesis of the tumor and its morphologic features culminating in a classic paper in Cancer in 1959. Although Teilum and others recognized that yolk sac tumor could be a component of mixed germ cell tumors, Talerman was one of the first to emphasize that, particularly in the testis, it was common to see yolk sac tumor as a component of a mixed germ cell tumor. Teilum, working in Copenhagen, and Talerman, when the former was alive, working in Rotterdam, developed a warm friendship in part due to their great interest in the yolk sac tumor, although it also extended to other areas of gonadal neoplasia and indeed beyond the boundaries of medicine when they shared time together. The typical histologic features of the yolk sac tumor are the reticular-microcystic patterns Teilum described, but various other patterns, including solid and even rarer ones such as glandular and hepatoid, are now well known. There are some interesting variations in the age distribution of this tumor at various sites: for example, vaginal examples are almost restricted to children under 2 years of age; those of the testis that are pure also occur mostly in young boys (average age about 20 months) but are occasionally seen in later years; ovarian examples peak at about 19 years of age; mediastinal forms are mostly restricted to young adult males. Brief consideration is also given to the occurrence of this tumor at well-known extragonadal sites such as retroperitoneum, mediastinum, and pineal as well as more exotic locations. Note is made of the recently emphasized occurrence of the yolk sac tumor on the background of a somatic neoplasm, most often endometrioid carcinoma of the ovary. Given the wide ranging and fascinating clinical and pathologic aspects of the neoplasm, it is no surprise that it continues to be a source of great interest to any pathologist who sees one or more examples, and we are indebted to Dr Teilum for his monumental studies and to Dr Talerman for his own contributions.

The detection and evaluation of human tumor metastases

Many biochemical indices are purported to have clinical utility in the detection and management of neoplasia. Experience gained during the past decade tends to indicate their having a more important role in the detection and monitoring of metastases than of the primary lesion. From this present review of some of the commoner human tumours, it is concluded that such marker substances are important adjuncts in the management of germ cell and certain endocrine and endocrine-related tumours. The carcinoembryonic antigen (CEA) provides a marker for many gastrointestinal cancers, but there are no presently available substances with clinical usefulness for either breast or lung neoplasms. Alternative approaches to the detection of metastases are also presented. The particular use of antibody probes at an immunohistochemical level has been claimed to be able to detect micrometastastic disease in bone marrow or tumour-related monoclonal antibody probes may have application to other cancers in the future.

Hypothesis: when is a seminoma not a seminoma?

Images

Hypothesis: when is a seminoma not a seminoma?

A xenograft line, HX 53, has been established in immune-suppressed mice from a specimen of a lymph node metastasis in a patient with a histological diagnosis of seminoma but with markedly raised circulating levels of alpha-fetoprotein. Histological, immunocytochemical, and ultrastructural studies of this xenograft line have suggested that a solid variant of yolk sac carcinoma may exist, which morphologically resembles seminoma, or that a continuum of differentiation exists between seminoma and yolk sac carcinoma.

Endodermal sinus (yolk sac) tumor elements in testicular germ-cell tumors in adults: comparison of prospective and retrospective studies

The incidence of endodermal sinus tumor (EST) or yolk sac tumor (YST) elements has been studied in two series of testicular germ-cell neoplasms in adults. One series, consisting of 200 germ-cell neoplasms seen from 1053 through 1968, was studied retrospectively, and the other, consisting of 147 cases seen from May 1974 through February 1979, was studied prospectively. Excluding the cases of pure seminoma, EST(YST) elements were found in 21 (28.7%) of 73 cases in the retrospective series and in 27 (44.4%) of 61 cases in the prospective series. The EST(YST) elements were in all cases admixed with other neoplastic germ-cell elements and varied from microscopic foci to being the predominant element within a tumor. The EST(YST) elements were histologically similar to infantile EST(YST) and EST(YST) in other locations. Serum alphafetoprotein (AFP) was determined in the majority of patients in the prospective series, and there was good correlation between the presence of EST(YST) elements within the tumor and elevated levels of AFP. The results of the present study indicate that EST(YST) elements occur quite frequently in testicular germ-cell neoplasms in adults and provide an explanation for the raised levels of serum AFP found in many adults with testicular germ-cell tumors. The results emphasize the importance of a thorough and careful pathologic examination of testicular germ-cell tumors, and the value of AFP as a tumor marker in patients with EST(YST). The results also lend further support to the view that EST(YST) elements found in testicular germ-cell tumors in adults are homologous with infantile EST(YST) and that EST(YST) is a distinctive and specific type of germ-cell neoplasm and should be included as such in the classification of testicular tumors.

Serum alphafetoprotein (AFP) in patients with germ cell tumors of the gonads and extragonadal sites: correlation between endodermal sinus (yolk sac) tumor and raised serum AFP

During the last 6 1/2 years, serum AFP has been determined by radioimmunoassay in 387 patients with germ cell tumors of the gonads and extragonadal sites. The histological appearances of all these neoplasms were carefully reviewed. Highly elevated levels of serum AFP were noted in patients with tumors containing endodermal sinus (yolk sac) tumor elements irrespective of the location of the neoplasm or presence or absence of metastatic disease. There was good correlation between the presence and quantity of endodermal sinus (yolk sac) tumor elements within the primary tumor or its metastases and elevated levels of serum AFP. All patients with tumors composed of pure seminoma or dysgerminoma, and teratoma, had normal serum AFP levels. Slightly elevated levels of serum AFP up to 60 ng/mg (upper limit of normal 20 ng/ml) were noted in a few patients with testicular tumors composed of pure embryonal carcinoma, whereas patients with tumors composed of or containing endodermal sinus (yolk sac) tumor elements had serum AFP levels that could be measured in 100's or 1000's of ng/ml. Serum AFP was elevated only in patients with active disease. Serum AFP was determined in 81 patients with gonadal tumors of non germ cell origin and was normal in all these patients. Serum AFP is a very good tumor marker in patients with germ cell tumors composed of or containing endodermal sinus (yolk sac) tumor, irrespective of their location. Serial serum SFP determinations can be used for diagnostic purposes, for monitoring the results of treatment, and for early detection of metastases and recurrences. Serial serum AFP determination is a useful procedure in all patients with germ cell neoplasms and is highly recommended.

Yolk sac carcinoma (endodermal sinus tumor): ultrastructure and histogenesis of gonadal and extragonadal tumors in comparison with normal human yolk sac

Human yolk sac carcinomas have been studied only twice with the electron microscope, and have never been compared at this level with normal human yolk sac. In the present study, the ultrastructural features of three primary ovarian yolk sac carcinomas, omental metastases from one of these, and a primary retroperitoneal yolk sac carcinoma in a male are reported, as are the ultrastructural findings in human yolk sac from normal 7- and 12-week gestations. The most prominent feature of the tumors is the presence of voluminous basement membrane material (the nature of which is confirmed by indirect enzyme-labeled antibody technique in one case) in both intra-and extracellular location, corresponding to the PAS-positive hyaline globules seen in these tumors by light microscopy. The tumor cells are also demonstrated to produce this material in tussue culture. Although basement membrane has not been described previously in normal human yolk sac at 8 and 10 weeks' gestation, it was present in the 7-week specimen which we studied, suggesting that its production may be a feature of only very young sac. Other ultrastructural findings are also similar in human yolk sac carcinoma, normal human yolk sac, and rodent yolk sac and yolk sac carcinomas. Thus, these studies confirm the suggested germ cell-derived yolk sac origin of the human tumor.

Features of prognostic significance in testicular germ cell tumours

One hundred and one testicular tumours previously diagnosed as "teratoma" were examined and 93 of the patients were followed up. These neoplasm were assigned to one of three groups. Those compared exclusively of somatic tissues were the only tumours referred to as teratoma. The second group was exclusively extra embryonic and consisted of either yolk sac or choriocarcinoma. Neoplasms in the third group were called mixed germ cell tumours and incorporated somatic and extra embryonic tissue and occasionally seminoma. The patients with teratomas showed a very low mortality whereas pure yolk sac tumours proved highly malignant. In mixed germ cells tumours the malignant nature of the yolk sac components was maintained even when combined with somatic elements, but when seminoma was also present the survival rate was significantly improved. It would appear the yolk sac tumour tissue occurs more frequently in adult testicular neoplasms than was previously suspected and in mixed germ cell tumours it can be expected to dictate behaviour except when combined with seminoma.

Gonadal and extragonadal yolk sac carcinomas: a clinicopathologic study of 14 cases

Fourteen cases of yolk sac carcinoma, 10 occurring in gonadal, and four in extragonadal sites, seen at the Indiana University Hospitals from 1949 to 1974, were analyzed with respect to pathologic features, laboratory findings, and clinical course. Their histologic appearance was similar regardless of the site of origin. Two basic histologic types were observed--the more common endodermal sinus pattern and the rare polyvesicular vitelline form. The prognosis is unfavorable, but three of our cases exhibited objective responses to chemotherapy. In our small series, the better prognosis of testicular yolk sac carcinomas in children found by some authors was not evident. Four of the 6 patients with yolk sac carcinoma in which serum alpha-fetoprotein determinations were performed showed positive results. Three of these cases had residual or metastatic disease clinically. The demonstration of alpha-fetoprotein in the serum of patients with yolk sac carcinoma lends further support to the yolk sac origin of these tumors and could also prove to be of prognostic value by indicating the presence of residual or recurrent disease.

The incidence of yolk sac tumor (endodermal sinus tumor) elements in germ cell tumors of the testis in adults

The incidence of yolk sac tumor (endodermal sinus tumor) elements was studied in 147 germ cell neoplasms of the testis in adults observed over a 4 1/2-year period. Excluding 79 cases of pure seminoma, yolk sac tumor elements were found in 26 (38%) of 68 tumors; in 8 tumors the yolk sac tumor was the predominant element. Yolk sac tumor elements were found admixed with all other germ cell tumor elements. Tumors composed entirely of yolk sac tumor were not encountered. Fifteen (57%) of the 26 patients with tumors containing yolk sac tumor elements have died of their disease during the period under study, compared with 13 (31%) of the remaining 42 patients, suggesting that the prognosis of adults with testicular tumors containing yolk sac tumor elements is unfavorable. This is in contrast to the relatively good prognosis of infants and young children with testicular yolk sac tumor, and similar to the prognosis of female patients with ovarian yolk sac tumor. The results of the present study give further support to the view that yolk sac tumor (endodermal sinus tumor) is not adistinctive neoplasm of the infant's testis, but a germ cell neoplasm differentiating in the direction of yolk sac or vitelline structures, and occurring in the testis, ovary and extragonadal sites in common with other germ cell neoplasms.