DNA topoisomerase I and II expression in drug resistant germ cell tumours

A small number of testicular germ cell tumours are refractory to current chemotherapy regimens. DNA topoisomerase I is the target for several new drugs and a potential candidate treatment for chemorefractory germ cell tumours. DNA topoisomerase II alpha is the target for etoposide, which is currently used regularly in germ cell tumour treatment. The expression of DNA topoisomerase I and II alpha were therefore assessed immunohistochemically in a range of testicular tumours, especially those with persistent malignant elements on retroperitoneal lymph node dissection. Pre-chemotherapy orchidectomy specimens were matched with post-chemotherapy retroperitoneal lymph node dissections to examine changes in expression. There was considerable variation in the expression of topoisomerase I in different tumour types. Both yolk sac tumours and teratoma, mature showed universal expression of topoisomerase I, while 38% of seminomas and 30% of embryonal carcinomas were positive. Strong topoisomerase II alpha expression was found in embryonal carcinoma. There was a negative correlation between topoisomerase I and II alpha expression (P=0.004) and downregulation of topoisomerase II alpha after chemotherapy (P=0.02). Topoisomerase I expression appears to increase in those cases with residual teratoma, mature, but is largely unchanged in those cases remaining as embryonal carcinoma. These results suggest that topoisomerase I inhibitors may be useful in chemorefractory germ cell tumours, especially yolk sac tumours and where there are unresectable residual teratoma, mature deposits.     

Antikeratin antibodies in tumor diagnosis. Distinction between seminoma and embryonal carcinoma

The authors investigated the presence and distribution of keratin in germ cell tumors using a rabbit-anti-keratin antiserum and a monoclonal antikeratin antibody--which is specific for keratin classes of 40, 50, and 56.5 kdaltons--by various immunohistochemical methods on frozen sections, alcohol-fixed, and formalin-fixed paraffin-embedded tissues. Thirty-four germ cell tumors were studied. These were the following: 18 seminomas, 10 embryonal carcinomas, 2 teratocarcinomas, 3 yolk sac tumors and 1 choriocarcinoma. All seminomas, including four poorly differentiated (so-called anaplastic seminomas), gave negative results, regardless of the method employed. Embryonal carcinoma, the epithelial component of the teratocarcinoma, the yolk sac tumors, and choriocarcinoma were at least focally positive for keratin. The monoclonal antibody provided a cleaner background and stronger staining than the rabbit-anti-total-human-epidermal-keratin antibody. Best results were obtained from fresh-frozen sections or alcohol-fixed, paraffin-embedded materials. Formalin-fixed, nonseminomatous tumors, when predigested with trypsin and incubated overnight with primary antibody, gave no false-negative results but staining was often focal. The authors' results agree with the reported absence of detectable keratin in primordial germ cells of the normal testis, and with prevailing concepts of the histogenesis of germ cell tumors. These results indicate that the presence or absence of keratin by immunocytochemical methods can be helpful in distinguishing seminoma from embryonal carcinoma.     

Yolk-sac carcinoma develops spontaneously as a late occurrence in slow-growing teratoid tumors produced from transplanted 7-day mouse embryos

Seven-day embryos of BALB/c mice transplanted underneath the kidney capsule of adult syngeneic recipients form either benign teratomas or teratocarcinomas, which can be distinguished from one another histologically at 8 weeks post-embryonic transplantation. Embryo-derived (ED) teratomas were allowed to remain in the host for an additional period up to 1 year after embryo transplantation, to test their malignant potential. It was found that a considerable number of slow-growing small tumors derived from embryonic transplant give rise to parietal yolk-sac carcinomas. A proportion of these tumors contained foci of visceral yolk-sac and trophoblastic differentiation, which gradually disappeared in successive transplantations. We conclude that parietal yolk-sac carcinoma develops as a late event in some ED teratomas. These malignant tumors originate either from small foci of yolk sac originally included in the grafted embryo or, more likely, from the yolk sac formed from the differentiating embryonic stem cells.     

The characteristics of embryonal carcinoma cells in teratocarcinomas

The orchiectomy specimens and the respective lymphadenectomies of 33 teratocarcinomas (teratoma and embryonal carcinoma) and 30 embryonal carcinomas were identified in a series of 457 consecutive germ cell tumors of the testis. Although teratocarcinomas were larger tumors the retroperitoneal lymphadenectomies revealed metastases in only 10 of 33 (30%) teratocarcinomas as compared to 19 of 30 (63%) embryonal carcinomas. Even after subtracting the teratoma component and stratifying for size of the embryonal carcinoma component, the teratocarcinomas were still less likely to metastasize than comparably sized pure embryonal carcinomas. Statistical significance was found between the differences in size and the differences in the rates of metastases, before and after stratifying for size of the embryonal carcinoma component of the teratocarcinomas. Further, all embryonal carcinomas metastasized as embryonal carcinoma while only 5 teratocarcinomas metastasized as embryonal carcinoma. This study supports experimental evidence that the embryonal carcinoma cells in teratocarcinomas are not necessarily identical to embryonal carcinoma cells in embryonal carcinomas.     

Human germ cell tumours: expression of gamma-glutamyl transpeptidase and sensitivity to cisplatin.

Previous studies have shown that the enzyme-glutamyl transpeptidase (GGT) is essential for the nephrotoxicity of cisplatin. This study was designed to determine whether GGT activity is necessary for the therapeutic effect of the drug. The relationship between GGT expression and clinical response to platinum-based chemotherapy was examined in 41 human germ cell tumours. Sections of formalin-fixed, paraffin-embedded tumours were immunohistochemically stained with an antibody directed against human GGT. There was no expression of GGT in any of the 17 seminomas or four dysgerminomas; whereas, 12/12 ovarian yolk sac tumours and 4/4 embryonal carcinomas of the testis were GGT-positive. In stage I tumours fewer tumour cells expressed GGT than in later stage tumours. In four germ cell tumours of mixed histology, the seminomatous and dysgerminoma areas were GGT-negative while the areas of the tumour with yolk sac or embryonal histology contained GGT-positive tumour cells. The patients with seminomas or dysgerminomas who were treated with cisplatin-based chemotherapy, all had a complete response despite the absence of GGT expression in these tumours. Fifteen of the 16 patients with yolk sac or embryonal carcinomas received cisplatin-based chemotherapy following surgery. Twelve had a complete response, while three failed to respond to platinum-based therapy. There was no correlation between the level of GGT-expression and response to therapy in this group. Three of the four patients with tumours of mixed histology were treated with cisplatin-based therapy, and had a complete response. Therefore, expression of GGT is not necessary for the therapeutic effect of cisplatin in germ cell tumours. The results from this study suggest that systemic inhibition of GGT would inhibit the nephrotoxic side-effect of cisplatin without interfering with its activity towards germ cell tumours.     

Involvement of dysadherin and E-cadherin in the development of testicular tumours

Testicular neoplasms are comprised of a variety of histologically different forms, and their pathogenesis has not been elucidated. Dysadherin is a recently described cell membrane glycoprotein, which has an anticell-cell adhesion function and downregulates E-cadherin. In this study, we examined immunohistochemically the expression of E-cadherin and dysadherin in 120 testicular neoplasms (37 seminomas-26 classic, five spermatocytic and six anaplastic-, 45 embryonal carcinomas, 10 mixed germ cell tumours, two yolk sac tumours, 10 mature and eight immature teratomas and eight non-Hodgkin B-cell lymphomas), clinical stage I. The intensity, the expression pattern and the percentage of neoplastic cell staining was recorded and correlated with the histologic type and vascular/lymphatic invasion. Dysadherin was not expressed in non-neoplastic germ cells, neither in CIS/ITGCNU, but it was highly expressed in all types of germ cell tumours, that demonstrated either embryonic phenotype or somatic differentiation, in most terminally differentiated neoplasms, and in all lymphomas. Dysadherin expression did not correlate with vascular invasion. Increased dysadherin expression was correlated with aberrant E-cadherin expression in most tumours. In 17% of embryonal carcinomas colocalisation of dysadherin and membranous E-cadherin staining was noted. This is the first report on dysadherin expression and its association with E-cadherin in testicular tumours. Since dysadherin is not normally expressed in non-neoplastic testis, it is conceivable that it plays a role in the neoplastic transformation of germ cells. In testicular tumours, as in other neoplasms, dysadherin downregulates E-cadherin expression, at least in part.     

Blood group-related antigens in human germ cell tumors

With the use of immunohistochemical techniques, seven mouse monoclonal antibodies and the lectin from Ulex europaeus, detecting blood group antigens of the ABH and Lewis systems, have been used to define the distribution of these antigenic structures in germ cell tumors. The reagents used recognize the following blood group antigens: A, B, H, Lewisa, Lewisb, X (Lewisx), Y (Lewisy), and type I precursor antigen. Tumors from 29 patients were studied. Tumors studied consisted of pure embryonal carcinoma for eight patients, pure yolk sac tumor for two patients, embryonal carcinoma plus yolk sac tumor in one patient, and yolk sac tumor plus seminoma in one patient. Also studied were nine classic seminomas and a group of six patients with tumors classified as seminomas that exhibited atypical histological features. One patient had an anaplastic carcinoma arising from the mediastinum which could not be conclusively identified as a germ cell tumor morphologically and was analyzed separately. All embryonal carcinomas and yolk sac tumors exhibited strong positivity for type I precursor structure as detected by the K-21 monoclonal antibody. In marked contrast, there was non staining in classic seminomas but heterogeneous staining in five of six atypical seminomas. The majority of embryonal carcinomas and all yolk sac tumors studied demonstrated strong positivity for blood group antigen H. For seminoma, however, only one of the atypical cases and two of the classic cases (occasional cells) stained for H. Focal expression of the Y antigen was identified in 5 of 17 seminomas and in the majority of embryonal carcinomas and yolk sac tumors. Two yolk sac tumors and two classic seminomas expressed blood group X. The remaining blood group antigens were not expressed by seminomas while they were variably expressed by embryonal carcinoma and yolk sac tumors. These data suggest that K-21 and blood group antigen H may be distinguishing markers of nonseminomatous germ cell tumor versus seminoma. If so, it is possible that the heterogeneous expression of blood group substances in seminomas with atypical histologies is an indication of differentiation towards nonseminomatous germ cell tumor.     

鞍区罕见肿瘤的临床诊治分析

目的 探讨鞍区罕见肿瘤的临床特点及其显微手术治疗,以提高对该病的诊治水平.方法 收集经显微手术治疗的6例鞍区罕见肿瘤患者的临床资料进行回顾性分析,并结合术前肿瘤标记物甲胎蛋白(AFP)和绒毛膜促性腺激素(HCG)联合检测与术后免疫组化染色指导后续治疗.结果 本组6例患者术前全部误诊,术毕病变镜下全切2例,大部切除4例.病理诊断肿瘤5例,炎性假瘤1例,病理类型分别为平滑肌肉瘤、卵黄囊瘤、混合性生殖细胞肿瘤、胚胎癌和毛细胞性星形细胞瘤及霉菌性炎性假瘤.术前AFP或HCG在卵黄囊瘤、胚胎癌和混合性生殖细胞瘤中均有不同程度升高.随访1个月至3年,卵黄囊瘤、胚胎癌和平滑肌肉瘤患者分别在术后5、6、10个月死亡,炎性假瘤患者术后2个月出现蛛网膜下腔出血,病情危重,余生存良好.结论 鞍区罕见肿瘤以高度恶性生殖细胞肿瘤为主,病理类型复杂,术前误诊率高,临床预后差.术前AFP和HCG联合检测对指导治疗、判断预后有一定意义.

Abstract：

Objective To investigate the clinical characteristics and microsurgical managements of rare tumors in the sellar region. Methods Six rare cases of tumors in the sellar region treated by microsurgery from Jan 2000 to Jan 2010 were reviewed retrospectively.Subsequent treatments were according to the status of preoperative alpha fetal protein(AFP) and human chorionic gonadotropin(HCG) measurement as well as confirmed by histopathological examination in all six patients. Results Total resection of the tumor was achieved in 2 cases and subtotal resection in 4 cases.Postoperative histopathology confirmed that the lesions were tumors in 5 cases and fungal pseudotumor in 1 case.Moreover,variety of histological types were observed in the present series,including leiomyosarcoma,malignant yolk sac tumor,mixed germ cell tumor,embryonal carcinoma,pilocytic astrocytoma and fungal pseudotumor,respectively.The serum levels of AFP and HCG were elevated to some extent in the patients with malignant yolk sac tumor,mixed germ cell tumor or embryonal carcinoma.Follow-up was conducted in all patients for 1 month to 3 years.The patients with malignant yolk sac tumor and embryonal carcinoma as well as leiomyosarcoma died in 5,6,10 months after operation,respectively.Subarachnoid hemorrhage occurred in the case of fungal pseudotumor at 2 months sfter surgery.The other two patients were surviving well. Conclusions Rare nongerminomatous malignant germ cell tumors are predominantly susceptible to the sellar region.Furthermore,High misdiagnosis rate and poor prognosis are characteristic in the present study.Dynamic AFP and HCG detection may play an important role in the diagnosis of those non-germinomatous malignant germ cell tumors located in the sellar region.The importance of awareness of the presence of such rare lesions in the sellar region is emphasized.     

Ultrastructural studies of xenografted human germ cell tumors

Xenografts have been established in immune-suppressed mice from three embryonal cell carcinomas, two yolk sac carcinomas, and a 'seminoma-like' tumor that produces alphafetoprotein. The ultrastructural features of these xenografts have been studied in detail and compared with human germ cell tumors removed from patients. A spectrum of ultrastructural differentiation has been demonstrated for tumors of the same histologic classification (embryonal cell carcinoma) and within individual tumors. Cells with ultrastructural appearances intermediate between seminoma and yolk sac carcinoma and between embryonal cell and yolk sac carcinoma have been demonstrated, and their potential implications for tumor histogenesis are discussed.     

Biologie und Pathologie von Keimzelltumoren des Hodens

Germ cell tumours constitute about 90% of testicular tumours and their incidence has increased in recent decades in Europe. The tumorigenesis of germ cell tumours shows remarkable similarities to embryogenesis and is discussed from a stem cell point of view. Invasive germ cell tumours develop from intratubular germ cell neoplasia and differentiate into seminomas and non-seminomas. The embryonal features of the persistent and neoplastic germ cells are transmitted to the invasive germ cells. Germ cell tumours display a broad histological variety resulting in a rather complicated WHO classification with multiple subtypes.     

Alpha-fetoprotein-producing non-germ cell tumours of the female genital tract

Elevated levels of alpha-fetoprotein (AFP), a foetal serum protein, occur mainly on the development of hepatocellular carcinoma (HCC) or germ cell tumours, including yolk sac tumour (YST) and embryonal carcinoma of the ovary. Rarely, other tumours of the female genital tract produce AFP. This article reviews the AFP-producing non-germ cell tumours reported in different parts of the female genital tract to date. These include different types of carcinomas and carcinosarcomas of the uterus, ovary and cervix and sex cord stromal tumours of the ovary. It is important for both pathologists and oncologists to be aware of such cases and the clinicopathological distinction from germ cell tumours, as the diagnosis would affect the management plan for the patient. The reviewed cases suggest that regardless of the patient’s age when no lesion is detected in the liver and stomach of a woman whose serum AFP level is abnormally high, the female reproductive system should be examined as a possible site of AFP-producing tumour. Biochemical, physiological and pathological features of AFP are briefly presented.     

A case of primary intrasellar malignant germ cell tumor

A case of a 13-year-old boy with a primary, intrasellar malignant germ cell tumor is reported. An immunohistochemical study revealed that the serum HCG and AFP levels were highly elevated and that the tumor contained elements of seminoma, choriocarcinoma, a yolk sac tumor, and an embryonal carcinoma. After operation, combined chemotherapy (cisplatin, vinblastine and bleomycin, i.e. PVB therapy) and irradiation were performed in hope of achieving the radiosensitizing effect of cisplatin. As a result, partial remission was obtained. Although PVB therapy is considered effective, combined radio-chemotherapy, as was done in this case, is thought to be better method for treating an intracranial, malignant germ cell tumor.     

SALL4 is a novel sensitive and specific marker for metastatic germ cell tumors,with particular utility in detection of metastatic yolk sac tumors

BACKGROUND:

The correct diagnosis of metastatic germ cell tumors is critical, because these tumors can be effectively treated and are even cured with modern therapy. Their histopathologic diagnosis can be challenging without immunohistochemical markers, which currently have limitations. SALL4 is a novel stem cell marker essential to maintain pluripotency and self‐renewal of embryonic stem cells. In the current study, the authors investigated the utility of SALL4 as a potential diagnostic marker for metastatic germ cell tumors.

METHODS:

Ninety metastatic germ cell tumors from testis, ovary, and extragonadal sites were stained with a monoclonal SALL4 antibody. In addition, 170 metastatic nongerm cell malignancies, including 158 carcinomas (6 head and neck, 8 thyroid, 12 lung, 8 breast, 7 hepatocellular, 3 cholangiocarcinomas, 2 ampullary, 10 pancreatic, 18 gastric, 15 esophageal, 10 renal cell, 10 urothelial, 12 prostatic, 18 ovarian, 6 uterine, and 13 colonic) and 12 melanomas, were also stained to test SALL4 specificity.

RESULTS:

All 22 seminomas, 7 dysgerminomas, 22 embryonal carcinomas, and 14 of 15 yolk sac tumors displayed strong and diffuse SALL positivity in >90% of tumor cells (80% of tumor cells were strongly positive in the remaining yolk sac tumor). Five of 7 choriocarcinomas and 9 of 18 teratomas were also variably positive for SALL4. In contrast, only 10 (esophageal, gastric, and colonic adenocarcinomas) of 170 metastatic somatic tumors demonstrated focally weak SALL4 reactivity (<25% tumor cells).

CONCLUSIONS:

SALL4 is a novel sensitive and highly specific marker for metastatic germ cell tumors, and is particularly useful for detecting metastatic yolk sac tumors. Cancer 2009. © 2009 American Cancer Society.     

Human chorionic gonadotropin and alpha-fetoprotein in testicular germ cell tumors. An immunohistochemical study in comparison with tissue concentrations

The relation between immunohistochemical demonstration and tissue concentration of humanchorionic gonadotropin (hCG) and alpha-fetoprotein (AFP) was examined in 17 testicular germ cell tumors. There was a good correlation between their results; e.g., a tumor with high hCG concentration contained numerous hCG positive cells, and vice versa. The immunoperoxidase localization of hCG and AFP was investigated in 57 tumors including above 17. HCG was revealed in syncytiotrophoblastic giant cells of seminoma or embryonal carcinoma as well as syncytial cells of choriocarcinoma, and on rare occasion in mononuclear cells. AFP was localized in tumor cells of yolk sac tumor or embryonal carcinoma and occasionally hyaline globules. No cell was stained concomitantly with hCG and AFP. Pathogenetical significance of cells positively stained was discussed.     

Embryonal carcinoma of the testis

Long-term survival rates were correlated with selected clinical features in 479 patients with embryonal carcinoma of the testis and 33 patients with endodermal sinus tumor (infantile embryonal carcinoma, yolk sac tumor). In the period 1977 to 1982 embryonal carcinoma accounted for 26.8% of newly diagnosed germ cell tumors and 43% of nonseminomatous germ cell tumors entered in the Centralized Cancer Patient Data System. Among patients with embryonal carcinoma, over 80% were diagnosed in the 15-to-34 year age group. Seventy-four percent of the patients had metastatic disease at the time of diagnosis, and 50% of these had distant metastases, attesting to the aggressiveness of embryonal carcinoma and its tendency to early hematogenous spread. Despite the highly malignant nature of the tumor, the overall 5-year survival rate with treatments used was an excellent, 88%. Survival was correlated with the extent of disease at the time of diagnosis; the 5-year actuarial survival rates for patients with localized, regional, and distant disease were 98%, 96%, and 74%, respectively. Endodermal sinus tumor was uncommon (1.8% of all testicular germ cell tumors), occurred predominantly in the younger age group (0-24 years), and in 50% of the cases was localized to the testis. The survival rate for the 33 patients with this form of tumor was slightly worse than for the "adult form" of embryonal carcinoma. The authors conclude that survival of patients with embryonal carcinoma has greatly improved over the last decade as a result of improved methods for early detection of metastatic deposits and the effectiveness of newer chemotherapies in the treatment of disseminated disease.