Retroperitoneal germ cell tumor treated by PVeBV chemotherapy: a case report.

The extragonadal germ cell tumor are uncommon neoplasms which account for only 1-5% of germ cell tumors, and its prognosis is poor. We report here the use of combination chemotherapy with cisplatin, etoposide, bleomycin, and vinblastine (PVeBV) for the treatment of retroperitoneal germ cell tumor. A 28-year-old male with complaints of abdominal pain and lumbago, without any abnormality in both testes by physical and ultrasonographic examination, showed retroperitoneal tumor by abdominal computed tomography. The serum alpha-fetoprotein and lactate dehydrogenase were elevated. The retroperitoneal tumor was treated surgically. The pathological diagnosis was mixed germ cell tumor. The lung and supraclavicular lymph node metastases disappeared completely after 3 courses of PVeBV chemotherapy with cisplatin (40 mg/m2 per day) and etoposide (100 mg/m2 per day) for 5 consecutive days, with vinblastine (0.2 mg/kg) on day 1, and bleomycin (30 mg/body) given on days 1, 8, and 15. Granulocyte colony-stimulating factor and serotonin receptor antagonist application were available on acute phase toxic effects. The patient is now alive and well, without recurrence, more than 26 months after the operation.     

Germ cell tumor of the testis--clinicopathologic analysis of 114 cases

The histologic features and clinical records of 114 cases of germ cell tumors of the testis proved by pathology in our hospital from 1951 to 1980 are reviewed. These cases were divided into six types: seminoma 49.1%, embryonal carcinoma 8.8%, yolk sac tumor 17.5%, choriocarcinoma 0.9%, teratoma 14.9% and mixed carcinoma 8.8%. The over-all incidence of metastasis observed on exploration was 41.2%, and in embryonal and mixed carcinoma it was the highest, each amounting to 80%. Site of metastasis was: inguinal and retroperitoneal lymph nodes 63.8%, mesenteric lymph nodes 6.4%, liver 12.8%, lung 8.5% and supraclavicular lymph nodes 8.5%. In the 24 followed cases, 13 were seminomas and 11 non-seminomatous germ cell tumors. 5 of the former and 9 of the latter died of the tumor. It is advised that, in addition to radical orchiectomy, supplementary radiotherapy to the original site in the testis and the retroperitoneal draining lymphatics be given to seminoma and retroperitoneal lymph node dissection be given to non-seminomatous germ cell tumors except the pure choriocarcinoma to improve the result.     

Retroperitoneal lymph node dissection in the treatment of low-stage nonseminomatous germ cell tumors of the testicle

Nonseminomatous germ cell tumors of the testicle are highly treatable and curable. The evolution of cancer control for this disease has demonstrated an effective integration of medical and surgical approaches over the last 30 years. Current emphasis in the therapy of nonseminomatous germ cell tumors focuses on minimizing treatment-related morbidity while maintaining consistently high cure rates. Retroperitoneal lymph node dissection in experienced hands is a critical component of the treatment armamentarium in this disease. Retroperitoneal lymph node dissection is an accurate staging tool that provides important information in determining the need for chemotherapy. When performed properly, retroperitoneal lymph node dissection eliminates the retroperitoneum as a site for relapse, which in turn provides emotional and psychological relief to the patient and simplifies the follow-up protocol. Retroperitoneal lymph node dissection alone can also provide high cure rates in patients with clinical low-stage disease and high-risk factors such as lymphovascular invasion or predominance of embryonal histology in the primary tumor. Teratoma is known to be chemoresistant and, when present in the primary tumor of low-stage patients, may be best treated with primary retroperitoneal lymph node dissection. Primary chemotherapy in the treatment of low-stage nonseminomatous germ cell tumors deserves continual investigation as long-term toxicities become more apparent. Observation is an option for the highly motivated patient, but requires a rigorous follow-up schedule to avoid relapse. Laparoscopic retroperitoneal lymph node dissection is a viable staging tool, however, oncologic control of the retroperitoneum has not been reliably determined.     

The role of chemotherapy and surgery in the treatment of retroperitoneal metastases in advanced nonseminomatous testis cancer

This study evaluates the effect of combination chemotherapy on retroperitoneal metastases from nonseminomatous germ cell tumors of the testis (NSGCTT). Sixty-six patients with Stage III or bulky Stage II NSGCTT with clinically documented retroperitoneal metastases first received systemic chemotherapy. Seventeen patients had minimal and 49 had advanced retroperitoneal metastases. The retroperitoneal metastases were classified as advanced if the patient had a palpable retroperitoneal mass, ureteral deviation on intravenous pyelogram, or a mass with a diameter greater than or equal to 5 cm documented by a computerized axial tomographic scan, a pedal lymphangiogram, or surgery. The patients with lesser but clinically evident retroperitoneal metastatic deposits were considered to have minimal retroperitoneal metastases. A complete remission of retroperitoneal metastatic deposits was achieved in 50 (76%) patients, with chemotherapy alone in 25 (38%), and with combined chemotherapy and surgery in 25 (38%). The resected deposits consisted of mature teratoma in 15 and malignant elements in 10. A complete remission using chemotherapy alone occurred in 13 of 17 (76%) with minimal and in 12/49 (24%) with advanced retroperitoneal metastases, and in 17/30 (57%) without and 8/36 (22%) with teratoma in the testis tumor. The data strongly implied that the bulk of the metastatic deposits was a more important prognostic variable than the histology of the primary tumor. The adverse relationship of a teratomatous differentiation on the response rates with chemotherapy alone was offset by the success of supplemental surgery. This study suggests the benefit of a postchemotherapy retroperitoneal lymph node dissection (RPLND) in patients with initially bulky retroperitoneal metastases (complete response [CR] increased from 24% to 67%; an additional 47% patients had no evidence of disease). The patients with minimal retroperitoneal metastases usually achieved a CR with chemotherapy alone. A routine RPLND after the chemotherapy is not indicated in patients with initially minimal retroperitoneal metastases.     

Malignant granulosa cell tumor of the testis associated with gynecomastia and long survival.

A case is reported of classic granulosa cell tumor of the testis with metastases to the retroperitoneal lymph nodes occurring in a 26-year-old man. The patient had left-sided testicular enlargement and bilateral gynecomastia. He was treated by radical orchiectomy, retroperitoneal lymph node dissection, and radiation therapy and is well without evidence of disease 14 years after diagnosis. This is the first documented case of granulosa cell tumor of the testis with metastases and long remission after successful therapy to the authors' knowledge.     

Extragonadal retroperitoneal germ cell tumor: evidence of origin in the testis.

BACKGROUND: The origin of extragonadal retroperitoneal germ cell tumors remains controversial. Whether they develop primarily in the retroperitoneum or whether they are metastases of a primary testicular tumor has long been debated. PATIENTS AND METHODS: We retrospectively analyzed 26 patients treated as having primary extragonadal retroperitoneal germ cell tumors based upon the findings of testicular palpation by the referring physician. Testicular evaluation was then extended with ultrasonographical and histological examinations. RESULTS: Biopsy of the extragonadal tumor was performed in 25 patients, confirming diagnosis of extragonadal retroperitoneal germ cell tumor. Prior to treatment patients were clinically evaluated by several physicians and the testes were not considered suspicious for testicular cancer. At urological workup, testes were found to be atrophic and/or indurated in 14 (54%) patients, enlarged in one (4%) and unremarkable in 11 (42%). Ultrasound examination of the testes in 20 patients showed pathological findings in all of them. Histology of the testis was available in 25 of 26 patients and revealed active tumor in three, intratubular germ cell neoplasia in four, scar tissue in 12, sclerosis in three, sclerosis and fibrosis in one, and fibrosis alone in two. CONCLUSIONS: So-called primary extragonadal germ cell tumors in the retroperitoneum are very likely a rare or non-existing entity and should be considered as metastases of a viable or burned-out testicular cancer until proven otherwise. All of our patients with histologically examined testes had pathological finding, 76% of which were either viable tumor or scars.     

腹腔镜及开放根治性肾输尿管膀胱切除术治疗输尿管癌合并膀胱混合癌1例报告及文献回顾分析

目的：探讨腹腔镜和开放根治性肾输尿管膀胱切除术治疗输尿管癌合并膀胱混合癌患者的可行性和安全性。方法：回顾分析1例单侧输尿管癌并浸润性膀胱混合癌,腹腔镜下行根治性肾输尿管膀胱切除术及开放尿流改道手术患者的临床资料并进行随访分析。结果：术前经B超、CT、膀胱镜、输尿管镜和静脉肾盂造影等检查证实为左输尿管癌并浸润性多发膀胱癌,行腹腔镜肾输尿管膀胱切除术及开放尿道切除术和右侧输尿管皮肤造口术,手术时间480min,术中出血量约560ml,无输血。术后肠功能恢复时间为3d,下床活动时间4d。术后未出现并发症。术后病理结果为膀胱高级别泌尿上皮癌伴浸润性鳞状细胞癌侵及全层。左输尿管癌高级别泌尿上皮癌侵及全层。输尿管癌分期分级为T2N0M0,膀胱癌为T2N0M0。术后随访10月,患者无瘤生存至今。结论：单侧输尿管癌合并膀胱混合癌可行一期根治性肾输尿管膀胱切除术,腹腔镜下行该手术是可行及安全的。较开放手术创伤小,恢复快。膀胱混合癌很难早期确诊,为了使膀胱混合癌得到早期诊断和治疗,提高患者生存率,行膀胱镜检查时,应多位点取材。     

Mucosal metastases in malignant melanoma

BACKGROUND: We present the case of a patient with malignant melanoma stage IV according to the American Joint Committee on Cancer (AJCC) classification and an unusual pattern of metastasis to the mucosa of the esophagus, the stomach, the bladder and the palatine tonsil. CASE REPORT: A 38-year-old male patient with metastatic malignant melanoma of stage III (AJCC) was admitted for initiation of adjuvant therapy. 4 months earlier a primary melanoma of the left upper leg had been excised and 2 months later the patient had undergone a left inguinal lymph node dissection revealing 2 metastatic lymph nodes. On admission the patient complained of a sore throat and right cervical lymphadenopathy. He underwent a tonsillectomy and a lymphadenectomy which both revealed melanoma metastases. A PET scan using F-18-fluorodeoxyglucose (FDG) showed focal metabolic activity in the middle mediastinum. Two cycles of dacarbazine (DTIC) chemotherapy were performed during which the patient developed cutaneous metastases, dyspepsia, and mild hematemesis. Gastroscopy revealed bleeding from mucosal metastases of the esophagus and stomach. A few weeks later the patient developed macroscopic hematuria. A cystoscopy was performed and showed metastases to the mucosa of the bladder. Nutrient vessels of these bladder metastases were embolized in order to control bleeding. The patient is currently alive with progressive disease. RESULTS: This case presents common and uncommon sites of metastatic melanoma to the mucosa with the typical clinical manifestations in a single patient.     

Clonal origin of lymph node metastases in bladder carcinoma

BACKGROUND: Evidence of genetic heterogeneity within urothelial carcinomas of the bladder has raised questions about the clonal origin of urothelial carcinoma and its metastases. High-grade urothelial carcinoma of the bladder frequently metastasizes to multiple regional lymph nodes in the pelvis. Whether or not these multiple lymph node metastases originate from the same tumor clone is uncertain. Molecular analysis of microsatellite alterations and X-chromosome inactivation status of distinct tumor cell populations from the same patient may further our understanding of the genetic basis of carcinoma progression and metastasis. METHODS: The authors examined 24 patients who underwent radical cystectomy for urothelial carcinoma. All patients had multiple (from two to four) lymph node metastases. Genomic DNA samples were prepared from formalin fixed, paraffin embedded tissue sections using laser-assisted microdissection. Loss of heterozygosity (LOH) assays for 3 microsatellite polymorphic markers on chromosome 9p21 (D9S171, region of putative tumor suppressor gene p16), 9q32 (D9S177, putative tumor suppressor gene involved in urothelial carcinoma tumorigenesis), and 17p13 (TP53, the p53 locus) were performed. In addition, X-chromosome inactivation analysis was performed in primary tumors and metastases from 10 female patients. RESULTS: In total, 79 tumors were analyzed. The overall frequency of allelic loss was 67% (16 of 24 tumors) in the primary urothelial carcinomas and 79% (19 of 24 tumors) in the metastatic carcinomas. The primary urothelial carcinoma showed LOH at the D9S171, D9S177, and TP53 loci in 39% (9 of 23 tumors), 30% (6 of 20 tumors), and 30% (7 of 23 tumors) of informative samples, respectively. LOH in > or = 1 lymph node metastases was seen at the D9S171, D9S177, and TP53 loci in 35% (8 of 23 tumors), 45% (9 of 20 tumors), and 48% (11 of 23 tumors) of informative samples, respectively. Eleven tumors demonstrated identical allelic loss patterns at all DNA loci both in the primary carcinoma and in all corresponding lymph node metastases. Three tumors showed allelic loss in the metastatic carcinoma but not in its matched primary carcinoma. Six tumors demonstrated a different LOH pattern in each of its lymph node metastases. Clonality analysis showed the same pattern of nonrandom X-chromosome inactivation both in the primary urothelial carcinoma and in all of the lymph node metastases in five of nine informative tumors studied. Four tumors showed a random pattern of X-chromosome inactivation in both the primary carcinoma and in the metastases. CONCLUSIONS: LOH and X-chromosome inactivation assays showed that multiple lymph node metastases and matched primary urothelial carcinomas of the bladder had the same clonal origin, suggesting that the capability for metastasis often arises in only a single clonal population in the primary tumor. The variable LOH patterns observed in some of the tumors likely reflect genetic divergence during the clonal evolution of urothelial carcinoma.     

Treatment and prognosis of testicular seminoma

Although testicular germ cell tumor is a relatively uncommon disease, it is a relatively common type of malignant tumor among young men. Seminoma accounts for approximately 50% of all germ cell testicular tumors. Since the vast majority of patients with seminoma present with early-stage disease and the disease responds well to treatment, almost all of the patients are cured. Patients who have stage I disease without obvious metastatic lesions have two treatment options, surveillance or adjuvant retroperitoneal radiotherapy, following inguinal orchiectomy. Stage IIA disease with a relatively small retroperitoneal lymph node metastasis is generally treated by retroperitoneal radiation therapy, although systemic chemotherapy with carboplatin is an alternative treatment. For patients with bulky retroperitoneal lymph node or distant metastases (stage IIB, III), systemic chemotherapy including cisplatin and etoposide appears to be the standard approach. Recently, 85% to 90% of patients with stage III disease are cured. Thus, the current therapeutic goal is cure of the disease with the minimum of treatment sequelae.     

A case of breast cancer diagnosed by inguinal lymph node metastasis

We describe a case of a 58-year-old woman with right inguinal lymph node swelling and a T1 tumor in the right breast. She was referred with an 18-month history of the former complaint and a six-month history of the latter. Excisional biopsy of the inguinal lymph node revealed breast cancer metastasis. Radiographical examination showed no metastases to the lungs, liver or bone. Modified radical mastectomy was performed. Histological examination revealed solid tubular carcinoma, PT2, PM (axillary lymph node metastases 4/16), stage IV. Estrogen and progesterone receptors were negative. Three cycles of postoperative cyclophosphamide, adriamycin and 5-fluorouracil (CAF) chemotherapy were given, and the right inguinal area was irradiated with 40 Gy. The patient complained of swelling in both legs three years after surgery. Computed tomography revealed marked lymph node swellings in the pelvic cavity. She died six months later. Inguinal lymph node metastasis from breast cancer is very rare, although distant lymph node metastasis in the cervix occurs frequently. This case should help clarify how breast cancer metastasizes to distant lymph nodes.     

Extragonadal Germ Cell Tumor of Retroperitoneal Origin: Report of Two Cases

Two cases of primary extragonadal germ cell tumor of retroperiotonealorigin are reported. One was a 26-year-old man complaining ofback pain. He had a large retroperitoneal tumor with lung, liverand supraclavicular lymph node metastases. He was referred tous after being treated for malignant lymphoma. The serum AFP,beta-subunit of human chorionic gonadotropin (hCG-beta), CEAand CA-19-9 were elevated. The retroperitoneal disease was treatedsurgically and with radiotherapy. The pathological diagnosiswas that of embryonal carcinoma and teratoma. The lung, liverand supraclavicular lymph node metastases disappeared completelyafter two courses of cisplatin-based chemotherapy. While furtherchemotherapy was postponed due to myelosuppression, the diseaserelapsed and was resistant to subsequent therapy. The patientdied twelve months after he first saw us. The second case wasthat of a 36-year-old man complaining of edematous legs andexternal genitalia. He had an extensive retroperitoneal tumor,with multiple pulmonary metastases. The serum AFP level washigh. Suspected of having an extragonadal germ cell tumor, hewas referred to us promptly. Cisplatin-based chemotherapy coupledwith resection of residual retroperitoneal and pulmonary diseaseresulted in complete remission. The pathological diagnosis wasthat of possible embryonal carcinoma. Further chemotherapy wasgiven as scheduled, using granulocyte colony-stimulating factor.The patient has been in complete remission for two years. Thechemotherapeutic regimen and surgical policy in the treatmentof the two patients were essentially same. Early diagnosis,adequate initial therapy and the use of granulocyte colony-stimulatingfactor may be relevant to the favorable prognosis in the lattercase.     

Malignant adenomyoepithelioma of the breast: a case with distant metastases

Adenomyoepithelioma is thought to be a low-grade malignancy, and cases showing malignant behavior are rare. A massive breast tumor with skin invasion in a 60-year-old woman was diagnosed as malignant adenomyoepithelioma. Despite the tumor size and skin invasion, no axillary lymph node metastases were detected. Light microscopy showed proliferation of tubular structures composed of atypical epithelial and myoepithelial cells and occasional anaplastic cells with mitotic figures extending to the epidermis of the skin. Twenty-four months after the surgery the patient complained of dull pain in the right thigh, and was found to have bone, lung and mediastinal lymph node metastases. There was neither local recurrence nor axillary lymph node metastasis. Subsequent femur fracture was treated by osteotomy. Despite additional chemoradiotherapy, the patient died 43 months after the first operation. Our case and literature review indicated that this tumor tends to show hematogenous metastasis.     

Seminoma metastases mimicking primary pancreatic cancer

BACKGROUND: A case of seminoma clinical stage III, arising from the right testis and mimicking a primary pancreatic malignancy is reported. CASE REPORT: A 57-year-old male patient presented with obstructive jaundice. He suffered from recurrent abdominal pain and significant weight loss over the past 4 months. Abdominal CT scan showed a tumor in the head of the pancreas and multiple pathologically enlarged peripancreatic lymph nodes. In the laboratory findings there were signs of cholestasis and infection. A laparoscopic biopsy out of a suspicious lesion of the head of the pancreas and a surrounding lymph node was done. Histopathological examination reported metastasis of seminoma in a lymph node. Further laboratory findings showed an elevation of the human placental alkaline phosphatase (HPLAP) and urological examination revealed a suspect right testis. The patient underwent castration of the right testis and histopathological examination confirmed a seminoma. 4 cycles of chemotherapy including cisplatinum, etoposide and bleomycin led into complete response that is still ongoing. CONCLUSION: This case shows a seminoma with metastases at retroperitoneal site, mimicking a primary pancreatic neoplasm. It provides an example of the possibility of an uncommon clinical appearance of seminoma metastases and again underlines the importance of exact radiological and histopathological examination to distinguish between curable and incurable tumor.     

What is the Role of Enlarged Lymph Node Resection Alone in Patients With Nonseminomatous Germ Cell Tumor Who Had Stage II or III Disease?

BackgroundRetroperitoneal lymph node dissection is an important treatment modality in nonseminomatous germ cell tumors of the testis. However, the role of more limited surgical approaches such as resection of enlarged lymph nodes only is still controversial.Patients and MethodsBetween January 1991 and December 2010, charts of 94 patients who underwent resection of enlarged retroperitoneal lymph nodes alone were reviewed. Pathologic findings, local recurrence, and adverse effects were noted after this surgical approach.ResultsThe median age was 25.5 years. Twenty-one (22.6%) patients had lung metastasis, and 5 (5.4%) patients had nonregional lymph node metastasis at the initial visit. Eighty-seven (91.6%) patients received chemotherapy after inguinal orchiectomy, and the other patients had mass resection only for enlarged lymph nodes without prior chemotherapy. In patients who had chemotherapy before surgery, the median retroperitoneal lymph node size before and after chemotherapy cycles was 55 mm and 32.5 mm, respectively. The pathologic assessment of retroperitoneal masses revealed mature teratoma in 51.6% (n = 47) of patients, viable carcinoma in 20.9% (n = 19) of patients, and necrosis or fibrosis in 27.5% (n = 25) of patients. The median follow-up time was 60.2 months (range, 2.7-334.8 months). During follow-up, 5 (5.4%) patients had radiologic relapse at the retroperitoneal area, and 3 patients developed systemic metastases. Six (6.4%) patients died of their disease, 2 (2.1%) patients were alive with disease, 86 (91.5%) patients were healthy at the last follow-up. Ejaculation status was recorded in 56 patients. Antegrade ejaculation had preserved in 53 (94.6%) of these patients.ConclusionsResection of enlarged lymph node metastases alone is a reasonable treatment option for patients with nonseminomatous germ cell tumors.     

Juvenile granulosa cell tumor of the ovary presenting with pleural effusion and ascites

Juvenile granulosa cell tumor (GCT) is a rare tumor, and the majority (90%) are reported in the prepubertal or under-30-year age group, in contrast to the adult type, which is more common in the fifth decade. On histopathological examination, juvenile GCTs are distinct from the adult type of GCT, and have a lower risk for late recurrences than the latter. Being solid tumors, they may be associated with ascites and pleural effusion (Meigs’ syndrome), which resolve after surgical removal of the tumor. Tumor markers for GCT are still investigational (inhibin) and of not much use in making a preoperative diagnosis, unlike in the case of germ cell tumors. In most of the reports about the initial surgical management of GCT, retroperitoneal lymph node sampling was not performed, and it was not done in the patient we report here. However, lymph node sampling is advocated for complete staging of these tumors, as a significant number of recurrences are reported in the retroperitoneum, as well as in incompletely staged patients. In the present patient, because of the association of Meigs’ syndrome, a preoperative diagnosis of benign tumors such as fibroma/thecoma was also considered. We report this rare tumor with an aim of reviewing the diagnosis and management from the reported literature.     

脉冲式低剂量率放疗治疗胃癌腹膜后淋巴结转移1例报道并文献复习

目的:本文通过病例报道及文献复习探讨脉冲式低剂量率放疗(pulsed reduced dose-rate radiotherapy,PRDR)治疗胃癌腹膜后淋巴结转移灶的可行性。方法:对1例胃癌术后腹膜后淋巴结转移致腰背部疼痛的病例应用脉冲式低剂量率放射治疗，结合临床资料，随访观察治疗效果并复习国内外相关文献。结果:该患者治疗前腰背部疼痛严重影响生活质量，影像学提示腹膜后巨大淋巴结肿大影。采用脉冲式低剂量率放疗治疗后靶区转移灶体积缩小90%以上，腰背部疼痛消失，复查CT疗效评价达到部分缓解。放疗后无进展生存期（progression-free survival，PFS）达11个月。结论:胃癌腹膜后淋巴结转移灶因解剖位置特殊导致无法耐受常规放疗的毒性，而应用脉冲式低剂量率放疗可以在降低不良反应的同时提高疗效，延长生存期，提高生存质量。因此脉冲式低剂量率放疗可作为胃癌腹膜后淋巴结转移患者的一个治疗选择。     

Retroperitoneal mature teratoma after orchidectomy for a stage IB pure embryonal testicular carcinoma

Nonseminomatous germ cell tumor of the testis stage I will relapse in approximately 30% of patients in the first year after orchidectomy. We report a 19-year-old patient on active surveillance who presented with a retroperitoneal lymph node enlargement suggestive of metastatic disease more than 1 year after the initial diagnosis of embryonal carcinoma stage IB. Complete resection of the lymph node was performed and showed the presence of mature teratoma. Our patient had an unusual case of metastasis formation of benign histology of a previously removed highly malignant primary tumor confined to the testis.     

Effects of multiple-drug chemotherapy (cis-diammine-dichloroplatinum, bleomycin, and vinblastine) on the maturation of retroperitoneal lymph node metastases of nonseminomatous germ cell tumors of the testis. No evidence for De Novo induction of differentiation

Investigating the mechanisms underlying maturation of metastases of nonseminomatous germ cell tumors on administration of chemotherapy, the histologic characteristics of primary testis tumors was compared to the histologic characteristics of their retroperitoneal metastases in three historical patient groups. The metastases in Group I (20 patients) were not treated; those in Groups II (nine patients) and III (24 patients) were treated, respectively, with three cycles of dactinomycin and with four cycles of cis-diammine-dichloroplatinum, vinblastine, and bleomycin, before retroperitoneal lymph node dissection. In Group III there was a significant increase of metastases consisting of differentiated teratoma only, as compared to the metastases of Group I. However, both with and without chemotherapy, the metastases contained fewer areas of differentiated teratoma than the primary lesions. Metastases containing differentiated teratoma with and without other components, with one exception in Group III, were derived from primary tumors containing mature areas as well. Components other than mature teratoma were almost completely eradicated in Group III. These findings strongly suggest that selective destruction of components other than differentiated teratoma causes the mature histologic characteristics in the metastases upon administration of chemotherapy. The results do not support the hypothesis of induction of differentiation by the chemotherapeutic agents.