Primary Seminoma (Germinoma)

Transcription

1 CASE REPORTS Primary Seminoma (Germinoma) of the Mediastinum William P. Kleitsch, M.D., Alfred Taricco, M.D., and George J. Haslam, M.D. P rimary mediastinal tumors of germinal cell origin, such as teratoma, teratocarcinoma, choriocarcinoma, and seminoma, have been the subject of frequent reports and are believed to be among the most common primary tumors of the anterior mediastinum. Pure seminomas or germinomas, however, appear to be the most rare of the germinal cell tumors, and their incidence seems to be confined to males. This is a case report of a pure seminoma (germinoma) occurring in the anterior mediastinum in relation to the thymus gland, and which apparently was eradicated by conventional, deep radiotherapy. L. C. I., a 54-year-old white male, was admitted to the Omaha VA Hospital in January, 1965, for treatment of a fractured left humerus sustained in a fall. He was a chronic alcoholic and drank as much as a fifth of whiskey a day. He had been treated for cirrhosis of the liver with ascites just prior to admission to our hospital. On physical examination he was found to be a well-developed, well-nourished white male in no acute distress with a contusion of the left temple and with the left arm in a posterior splint. The liver was palpable 15 cm. below the right costal margin in the midclavicular line. The right testicle was somewhat smaller than usual, and there was a varicocele on the left. The remainder of the physical examination was noncontributory. The serum bilirubin was 4 mg. per 100 ml. with a direct reading of 2 mg. per 100 ml.; serum protein was 5.9 gm. per 100 ml. with 2.6 gm. per 100 ml. of albumin and 3.3 gm. per 100 ml. of globulin. The cephalin flocculation was 3+ in 24 and 48 hours. These laboratory data were interpreted as supporting a diagnosis of Laenncc s cirrhosis of the liver, and this was confirmed by a needle From the Surgical Service of the Veterans Administration Hospital, Phoenix, Ariz. Accepted for publication April 18, 1967.

2 KLEITSCH, TARICCO, AND HASLAM A.FIG. 1. its growth in one month s time (R). Preoperative x-rays of the chest showing the mediastinal tumor (A) and biopsy. An x-ray of the chest (Fig. 1A) showed a large, left hilar mass which was thought to be either a tumor or an aneurysm. Oblique x-rays localized the mass to the anterior mediastinum, and fluoroscopic examination found the mass to be nonpulsatile and distinct from the aorta. Bronchoscopic examination of the tracheobronchial tree revealed marked posterior angulation of the trachea and marked deviation to the right with compression of the left lateral wall. Although the patient appeared to be euthyroid, the possibility of a retrosternal goiter was entertained; further studies revealed that protein-bound iodine and radioactive iodine uptake were within normal limits. A scintogram showed a thyroid gland which was normal in size and anatomical location, and there was no evidence of a substernal extension. During these studies he was treated intensively for his hepatic disorder. The cirrhosis responded to treatment, and a month after admission the liver was no longer palpable. B FIG. 2. Postirradiation x-ray showing complete regression of the mediastinal tumor shadow. 250 THE ANNALS OF THORACIC SURGERY

3 CASE REPORT: Seminoma of the Mediastinum A B FIG. 3. (A) A histological section of the tumor under low power, showing a highly cellular field of clear staining cells with scattered clumps of lymphocytes. (B) A histological section under higher power, showing typical seminoma cells with c,ear cytop.asm and prominent cell walls. The nuc'ei are distinct and demonstrate prominent nucleoli. VOL. 4, NO. 3, SEPT.,

4 KLEITSCH, TARICCO, AND HASLAM The mass in the chest, however, had grown at least 1 cm. in diameter during this period of time (Fig. 1B). An exploratory thoracotomy was then performed, and a tumor, 12 cm. in diameter, was found; it occupied the space between the pericardium, the arch of the aorta, and the sternum and projected into the left thorax. Because of direct invasion of the aorta, the tumor was judged unresectable and only a biopsy was obtained. The postoperative course after thoracotomy was without incident. He was referred for radiotherapy, and, using the standard 250- kilovolt apparatus, a dose of 3,200 rads was delivered to the tumor. He tolerated this treatment well, and a subsequent x-ray in July, 1965, showed no evidence of tumor (Fig. 2). The histopathology was reported as malignant tumor in the anterior mediastinum. It was thought that this represented a germinal cell tumor, possibly a seminoma (Figs. 3A, B). Pathological material was sent to the Armed Forces Institute of Pathology for their opinion. Their report said in part,... the histological pattern of nests of polyhedral cells with rather large, deeply stained nuclei separated by varying amounts of lymphoid granulomatous stroma is characteristic of seminoma-better referred to as germinoma, whether arising in the gonads or the mediastinurn.... Additional comment was made that seminomas, as well as other teratoid tumors of the mediastinurn,... can easily be shown to be associated with thymus gland and they are believed, according to one theory, to arise from germ cells which have migrated into the foregut and thymus gland during the embryologic development. In the present case, a few remnants of involved thymus tissue were seen in the fat immediately outside the capsule of the tumor. Reexamination of the testes revealed a 3 mm. indurated area at the inferior pole of the left testicle, easily felt when his varicocele became decompressed in the recumbent position. Because of the nature of the tumor in the chest, it was feared that this might be a primary growth. Therefore, an orchiectomy was performed 2 weeks after the thoracotomy. There was no tumor in the testis, which was atrophic. The patient was discharged from the hospital but did not do well, largely due to his chronic liver disease. In February, 1966, a partial gastrectomy was performed for a bleeding adenoma of the gastric antrum. At operation esophageal varices were visualized; a liver biopsy obtained at the same time was reported as Laennec s cirrhosis. Four months later, he was hospitalized and treated for ascites. In October, 1966, he was again hospitalized for ascites. During this hospitalization he showed increasing evidence of hepatic failure which became complicated by renal failure and oliguria. As a terminal event, he began to bleed from the upper gastrointestinal tract, and he died on November 11, An autopsy was performed, and the cause of death was found to be hemorrhage from esophageal varices secondary to portal hypertension due to advanced cirrhosis of the liver. A diligent search failed to discover any evidence of residual tumor either in the mediastinurn or elsewhere in the body. This then represents an eighteen-month follow-up, with autopsy confirmation, of tumor control by radiotherapy. DISCUSSION Although a pure seminoma is rarely found as a primary tumor of the mediastinurn, it is classified with others of germinal cell origin and is therefore included in the group of most common anterior mediastinal tumors. This group has been divided by Pachter and Lattes [6] into the following: adult teratoma, teratocarcinoma, choriocarcinoma, and seminoma. Steinmetz and Hays [12] offer a somewhat different 252 THE ANNALS OF THORACI.~ SURGERY

5 CASE REPORT: Seminoma of the Mediastinunz classification: (1) pure, which includes teratoma, chorionepitheliom, seminoma; and (2) mixed, which includes teratoma plus chorionepithelioma, and teratoma plus seminoma. The teratomas may be benign or malignant. The benign type seems to occur in a younger age group, is asymptomatic, and runs a universally benign course after the tumor is extirpated. Malignant teratomas comprise considerably less than one-half of this group and occur at an older age. They tend to have indistinct edges and are difficult to extirpate. They are almost always symptomatic. In addition, they are radioresistant. The net result of difficult surgical excision and radioresistance tends to make them a highly fatal type of tumor, survival being usually less than one year. Choriocarcinoma is a mediastinal tumor found less often. Only ten cases had been reported prior to 1958 [6]. All gave positive pregnancy tests. They seem to be even more malignant than the teratomas, and no one with this disease has survived beyond six months. The primary seminoma of the mediastinum, apparently of primitive germinal cell origin, is the most rare of the mediastinal tumors which apparently derive from germinal cells. Pachter and Lattes [61 found only one such instance in their series of 24 cases of germinal tumors of the mediastinum. It is true that many teratomas carry islands of seminomatous tissue in their bulk, and such instances are frequently reported. It is possible that the incidence of such islands is a function of the diligence with which they are searched for. The gross and microscopic anatomical description and classification of these tumors seem to be firmly established with only a minimum of terminological duplication. For instance, the popular term derrnoid has been incorporated into the more precise diagnosis, benign teratorna. However, when the problem of pathogenesis is encountered a diversity of opinion is found; this is well summarized by Schlumberger [lo]. The question of how germinal cells become sequestered in the anterior mediastinum to form a tumor in adult life remains largely unanswered. Even less clearly explained is why these tumors should occur in relation to the thymus and pineal glands. The explanation that such tumors are the result of faulty embryogenesis of the thymus seems to raise more questions than it answers. It is very probable that a more critical evaluation of tumors of the anterior mediastinum variously reported to be thymoma or undifferentiated carcinoma would result in an increase in the number of primary seminomas of the mediastinum available for study. There seems to be a decided tendency among pathologists, as reflected in the opinion expressed by the Armed Forces Institute of Pathology as quoted in their report, to accept the primary mediastinal seminoma as being of thymic origin. The case herein reported appears to be a tumor very similar in VOL. 4, NO. 3, SEPT.,

6 KLEITSCH, TARICCO, AND HASLAM nature to the primary seminoma of the testes before metastasis has taken place. The fact that the mediastinal seminoma will metastasize is attested to by several reports [6, 12, 141. That our experience with deep radiotherapy was most salutary suggests that the experience gained in the treatment of testicular seminomas should be applied to those originating in the mediastinurn. This implies surgical extirpation, if possible, followed by deep radiotherapy to the mediastinum. Should the tumor prove unresectable or excessively hazardous for resection, primary irradiation should be preferable to a life-threatening surgical procedure. A close follow-up of these patients is mandatory, and, should distant metastases become evident, tumoricidal irradiation to each individual metastasis is indicated. SUMMARY A case of primary pure seminoma of the anterior mediastinum is reported. The tumor was unresectable, but it proved to be highly sensitive to radiotherapy. An eighteen-month follow-up was terminated by death due to the complications of Laennec s cirrhosis of the liver. There was no evidence of residual or metastatic tumor found at autopsy. REFERENCES 1. Curreri, A. R., and Gale, J. W. Mediastinal tumors. A.M.A. Arch. Surg. 58:797, Friedman, N. B. Comparative morphogenesis of extragenital gonadal teratoid tumors. Cancer 4:265, Inada, K., and Nakano, A. Germinoma of the mediastinum: A case report with special reference to the histogenesis of mediastinal teratoma. Dis. Chest 36:438, Molina, C., Mercier, R., DeLage, J., delagvillamie, B., and Cheminat, J-C. Seminomas of the mediastinum. J. fr. Med. Chir. Thorac , Oberman, H. A., and Libcke, J. H. Malignant germinal neoplasms of the mediastinum. Cancer 17:498, Pachter, M. R., and Lattes, R. Germinal tumors of the mediastinum: A clinicopathologic study of adult teratomas, teratocarcinomas, choriocarcinoma and seminomas. Dis. Chest 45:301, Peabody, J. W., Strug, L. H., and Rives, J. D. Mediastinal tumors. A.M.A. Arch. Intern. Med. 93:875, Pugsley, W. S., and Carleton, R. L. Germinal nature of teratoid tumors of the thymus. A.M.A. Arch. Path. 56:341, Rubenstein, L. H. Tumors of the mediastinum. Chicago Med. 64:23, Schlumberger, H. G. Teratoma of the anterior mediastinum in the group of militar age: A study of sixteen cases, and a review of theories of genesis. Arch. Patl. 41:398, Schlumberger, H. G. Tumors of the Mediastinum. Atlas of Tumor Putholosy, Sect. I, Fasc. 18. Washington, D.C.: Armed Forces Institute of Pathology, Steinmetz, W. H., and Hays, R. A. Primary seminoma of the mediastinum: Report of a case with unusual site of metastases and review of the literature. Amer. J. Roentgen. 86:669, THE ANNALS OF THORACIC SURGERY

7 CASE REPORT: Seminoma of the Mediastinum 13. Watson, W. L., Pool, J. L., Cahan, W. G., Cliffton, E. E., Luomanen, R. J., and Goodner, J. T. The recognition of mediastinal tumors. GP 24:141, Woolner, L. B., Jamplis, R. W., and Kirklin, J. W. Seminoma (germinoma) apparently primary in the anterior mediastinum. New. Eng. J. Med. 252:653, VOL. 4, NO. 3, SEPT.,