Malignant germ cell tumors of the mediastinum

En bloc resection of an extremely giant mediastinal immature teratoma with somatic-type malignancy: A case report with a brief review of the literature

Primary mediastinum immature teratoma with somatic-type malignant transformation (SM) is extremely rare, and the clinical prognosis is poor. Immature teratoma with SM is difficult to eradicate by chemotherapy due to poor sensitivity; therefore, surgical resection is recommended whenever possible because it may offer better survival.

MRI Findings and Differential Diagnosis of Anterior Mediastinal Solid Tumors

The anterior mediastinum is the most common location of mediastinal tumors, and thymic epithelial tumors are the most common mediastinal tumors. It is important to differentiate thymic epithelial tumors from malignant lymphomas and malignant germ cell tumors because of the different treatment strategies. Dynamic contrast-enhanced MRI and diffusion-weighted imaging can provide additional information on the differential diagnosis. Chemical shift imaging can detect tiny fat tissues in the lesion and is useful in differentiating thymic hyperplasia from other solid tumors such as thymomas. MRI findings reflect histopathological features of mediastinal tumors, and a comprehensive evaluation of MRI sequences is important for estimation of the histopathological features of the tumor. In this manuscript, we describe the MRI findings of anterior mediastinal solid tumors and the role of MRI in the differential diagnosis.

Primary mediastinal germ cell tumors (PMGCT): A real-world analysis from a tertiary cancer care centre in India

BACKGROUND

Primary mediastinal GCT (PMGCT) is a rare entity and comprises 10-15% of all mediastinal tumors . We present our institutional experience of MGCT treated with multimodality management.

MATERIALS AND METHODS

We conducted a retrospective analysis between 2010 to 2020 of all mediastinal germ cell tumors registered at our center. Data on patient demographics, treatments received, treatment toxicities and response were recorded. Overall survival and relapse free survival were estimated using Kaplan-Meier methods.

RESULTS

A total of 30 patients were identified. The median age was 25.5 (range, 18-45) years. Common presenting features included cough (70%) and shortness of breath (70%) . Histology wise, 60% patients were non seminomatous histology whereas 33.3% patients were Seminoma.Twenty seven (90%) patients received chemotherapy as the first-line treatment, of whom five patients (16.6%) underwent surgery and radiation therapy subsequently. Median follow-up was 26.9 months. Thirteen patients (43.3%) had complete response (43.3%) and 8 patients had partial response (26.7%), while three patients (5.5%) had progressive disease. Three year relapse free survival rate was 69.6% (95% confidence interval [CI], 42.8-85.6%). Overall survival (OS) at 3 years was 73.4% (95% CI, 49.4- 87.3%). Patients with seminoma had a 3 year OS of 90.0% (95% CI, 47.3-98.5%) compared to those with non-seminoma (63.53% [95% CI, 32.3-83.3%]).

CONCLUSIONS

Multiagent chemotherapy is the backbone of treatement in PMGCT. Seminomatous PMGCT have excellent prognosis, while further improvement is needed in those with non-seminomatous tumor.

Primary mediastinal germ cell tumors

Mediastinal germ cell tumors share similar histopathological, immunohistochemical, and molecular features with their counterparts in the gonads. Therefore, proper clinical and radiological evaluation of patients with an anterior mediastinal mass becomes essential in the final interpretation of these tumors. The gold standard for the diagnosis of these tumors remains histopathological evaluation. However, immunohistochemical stains and molecular studies also provide an aid in cases in which the histology is not typical. It is also important to keep in mind that a small mediastinoscopic biopsy may not be representative of the entire neoplasm. In this review, we will provide our perspective regarding histopathological diagnosis, staging, immunohistochemical and molecular profile, and briefly family of tumors address pertinent epidemiological, clinical and treatment options. However, the main emphasis is to review the process of pathological assessment in pre and post-treated tumors. Knowledge of the different growth patterns and histological associations is important, mainly when confronted with mediastinoscopic biopsies, which ultimately will determine treatment options.

Primary mediastinal germ cell tumours: an immunohistochemical and molecular diagnostic approach

AIMS

Primary mediastinal germ cell tumours (PMGCTs) are rare mediastinal neoplasms and their diagnosis can be challenging due to small biopsy samples. The aim of this study was to elaborate a diagnostic algorithm using immunohistochemical stainings with focus on novel markers and molecular analysis of isochromosome 12p [i(12p)].

METHODS AND RESULTS

Paraffin-embedded tissues of 32 mediastinal tumours were analysed using immunohistochemical stainings for SALL4, LIN28, OCT3/4, D2-40, CD117, SOX17, SOX2, CD30, ß-hCG, GATA3, FOXA2, GPC3, AFP, TdT, NUT and pan-cytokeratin. Quantitative real-time polymerase chain reaction (qPCR) was performed to investigate i(12p) status. Fifteen seminomas, seven teratomas, one yolk sac tumour, one choriocarcinoma and seven mixed PMGCT were diagnosed. Each entity had different immunohistochemical staining patterns which helped to distinguish them: seminoma (OCT3/4, D2-40, CD117, TdT), embryonal carcinoma (OCT3/4, SOX2), yolk sac tumour (FOXA2, GPC3, AFP) and choriocarcinoma (ß-hCG, GATA3). Mature teratomas stained positive for pan-cytokeratin in epithelial components and focally for SALL4, SOX2, GATA3, D2-40 and FOXA2. Furthermore, a NUT carcinoma mimicking a PMGCT was diagnosed showing a strong nuclear SOX2 and speckled nuclear NUT staining. i(12p) was detected in 24 out of 27 PMGCTs [89%].

CONCLUSION

A diagnostic algorithm is of great importance for a reliable diagnosis of PMGCTs in the usually small tissue biopsy samples. Therefore, a combination of three to four antibodies to identify the correct histological subtype is usually necessary in addition to morphological features. The i(12p) status serves as an additional option to underline germ cell origin in selected cases.

Primary mediastinal germ cell tumours with high prevalence of somatic malignancy: An experience from a single tertiary care oncology centre

BACKGROUND

Primary mediastinal germ tumours (PMGCT) constitute, a mere 3-4% of all germ cell tumours (GCT). Although they account for approximately 16% of mediastinal tumours in adults and 19-25% in children as per western literature, there is hardly any large series on PMGCT reported from the Indian subcontinent.

DESIGN

We have retrospectively analysed clinicopathological features of 98 cases of PMGCT diagnosed over 10 years (2010-2019) from a tertiary-care oncology centre.

RESULTS

The study group (n = 98) comprised predominantly of males (n = 92) (M:F ratio-15:1), with an age range between 3 months to 57 years (median: 25 years). The tumours were predominantly located in the anterior mediastinum (n = 96). Broadly, Non-seminomatous germ cell tumours (NSGCT) were more common (n = 73, 74%) compared to pure seminoma (n = 25, 26%). Mixed NSGCT was the most common histological subtype (n = 30) followed by pure mature teratoma (n = 18), pure Yolk sac tumour (n = 13), mixed seminoma and NSGCT (n = 5), pure immature teratoma (n = 3) and GCT; NOS (n = 4). Interestingly, all female patients had exclusive teratomas. Nine cases revealed secondary somatic malignancy (5 carcinomas and 4 sarcomas). The majority of patients received neoadjuvant chemotherapy (n = 71). Surgical excision was performed in 60 patients. Follow up was available in 68 patients. NSGCT showed a poor prognosis as compared to seminoma (p value = 0.03) and tumours with somatic malignancies had a more aggressive clinical course.

CONCLUSION

PMGCT was seen predominantly in young adult males and somatic malignancies were noted in as high as 9% of cases. Patient with somatic malignancy have aggressive clinical course, hence, extensive sampling and careful histopathological evaluation are recommended for the identification and definitive characterization.

Imaging of the Anterior/Prevascular Mediastinum

Prevascular mediastinal masses include a wide range of benign and malignant entities. Localization of mediastinal masses to specific compartments together with characteristic imaging findings and demographic and clinical information allows formulation of a focused differential diagnosis. Radiologists may use these methods to distinguish between surgical and nonsurgical cases and thus inform patient management and have an impact on outcomes. Treatment of choice varies based on the pathology, ranging from no intervention or serial imaging follow-up to surgical excision, chemotherapy, and/or radiation.

Clinical Characteristics and Outcomes of Patients With Primary Mediastinal Germ Cell Tumors: A Single-Center Experience

Purpose: Primary mediastinal germ cell tumors (PMGCTs) are rare. The natural history and optimal treatment strategies still need to be defined. The aim of the study was to summarize the clinical characteristics, treatment outcomes, and prognostic factors of PMGCTs.

Methods: Twenty-four patients with PMGCTs who were treated from December 2008 to January 2019 were evaluated retrospectively. The Kaplan–Meier method and Cox regression analysis were used to evaluate factors associated with prognosis.

Results: The study population consisted of 23 male patients and 1 female patient. Five patients were diagnosed with seminoma and 19 patients were diagnosed with nonseminoma. The median follow-up time for all patients was 15.8 (3.9–114.5) months. The 5-year overall survival (OS) and progression free survival (PFS) rates for all patients were 65.2 and 44.3%. For nonseminoma and seminoma, the 5-year OS rates were 54.1 and 100% (P = 0.093), respectively, and the 5-year PFS rates were 28.7 and 100%, respectively (P = 0.044). In patients with nonseminoma, first-line radiotherapy indicated superior OS and PFS (P = 0.037 and 0.027, respectively). The median survival time after recurrence was 4.3 months and the 1-year survival rate after recurrence was 23.4%.

Conclusion: These results indicated that in PMGCTs, the prognosis of seminoma is superior to that of nonseminoma. Radiotherapy may be an essential treatment in patients with nonseminoma. Patients with relapse have unfavorable prognosis.

Mixed-type primary germ cell tumor of the mediastinum in a young adult male with a sudden life threatening condition: A case report

Primary germ cell tumors of the mediastinum are rare neoplasms. Above all, choriocarcinomas are highly aggressive with early haematogenous dissemination. Here, we report an extremely rare case of mixed‐type primary germ cell tumor of the mediastinum which occurred in a 26‐year‐old man with multiple metastases of the lung caused by choriocarcinoma components, with diffuse pulmonary hemorrhaging. The patient developed a sudden life threatening condition a few days after a needle biopsy.

Key points

Significant findings of the study: This was an extremely rare case of mixed‐type germ cell tumor in a young adult male who developed a sudden life threatening condition due to choriocarcinoma components just a few days after a needle biopsy.

What this study adds: Serious conditions may occur in patients with germ cell tumor containing choriocarcinoma components. At present, there is no other way to treat such patients than to promptly recognize complications and perform urgent multimodal intervention.

Metachronous Germ Cell Tumors of the Mediastinum

We report a rare case of mediastinal nonseminomatous germ cell tumor arising after 2 complete resections of mediastinal mature teratomas 18 and 10 years prior. After three cycles of chemotherapy for the mediastinal nonseminomatous germ cell tumor, the serum α-fetoprotein and β-human chorionic gonadotropin levels were normalized. However, chest radiography revealed that the mediastinal tumor had remarkably increased in size, and thus growing teratoma syndrome was diagnosed. The patient underwent urgent resection of the tumor, and a pathologic examination showed an encapsulated mature teratoma without any malignant viable cells. The patient was well without disease 54 months after the third operation.

Computed Tomography of Anterior Mediastinal Tumors

Computed tomographic (CT) features in 10 patients with germ cell tumor of the mediastinum and 15 with thymoma were compared with surgically resected specimens. The CT findings of the internal structure of tumors were the most important factor for specific diagnosis. Germ cell tumors showed a round mass without distinct lobulation, frequently with calcification appearing as a globular shape, and especially in benign tumors as an arched shape along the wall. Homogeneous low density masses (near-water) with a thick wall were benign and non-homogeneous density masses (a mixture of near-water and soft tissue) were malignant. Thymoma usually showed a solid mass with lobulation and sometimes had an eggshell type of calcification in the tumor. Therefore, CT is of importance in the diagnosis of anterior mediastinal masses.

Primary seminoma arising in the middle mediastinum: A case report

Primary mediastinal seminoma often occurs in the anterior mediastinum of young males. It is unusual for the tumor to originate in the middle or posterior mediastinum, and such cases have rarely been reported in the English literature. The present study reports the case of a 52-year-old man with a 3.0-cm primary seminoma arising in the middle mediastinum. The patient presented with the symptoms of cough and chest tightness. Fluorine-18 fluorodeoxyglucose-positron emission tomography (¹⁸F-FDG-PET) scans revealed unique abnormal FDG uptake in the middle mediastinum. A mediastinoscopy was performed and integral excision was found to be difficult. A biopsy was performed and the histological examination revealed a primary seminoma. Following 4 cycles of a standard bleomycin, etoposide and cisplatin chemotherapy regimen, and chest irradiation at a total dose of 40 Gy in 20 fractions, the tumor exhibited a partial response, decreasing in size, and FDG uptake was no longer observed on ¹⁸F-FDG-PET scan. The last follow-up date was April 2016 and the patient has remained disease-free for 20 months.

Robotic-assisted thoracoscopic resection of a benign anterior mediastinal teratoma

There is an emerging body of evidence to support robotic-assisted mediastinal surgery, particularly for thymectomy. We describe the case of a 42-year-old woman with a benign anterior mediastinal teratoma resected by robotic-assisted thoracoscopy. This case illustrates the use of robotic-assisted surgery in a less commonly encountered mass of the anterior mediastinum.

Primary mediastinal "thymic" seminomas

Over the last half century, our knowledge on germ cell tumors (GCT) has increased dramatically. Tumors that at one time were supposed to originate exclusively from certain anatomic areas are now thought to occur in ubiquitous distribution. Nevertheless, because of their similar histopathologic features, the conventional classic evaluation of these patients will require careful clinical history as well as complete physical and radiologic evaluation. The emphasis in this manuscript will be to highlight the occurrence and overall characteristics of one of the most common GCTs in the mediastinal region-seminoma. A more detailed discussion of mediastinal GCTs is well beyond the scope of this review.

[The clinical view through the Archives: the clinical notes of 2009]

The Clinical Notes published in 2009 serve as a resource to reflect on clinical aspects relevant to different clinical entities. Through this review an attempt is likewise made to bring the reader closer to the clinical reality of our environment.

Retropleural teratoma presenting as an abdominal mass in a 9-month-old boy

BACKGROUND

Teratomas are rare tumors that present most commonly in the anterior mediastinum and retroperitoneum. To date, the retropleural primary site has not been reported.

CASE PRESENTATION

A 9-month-old boy presented with a large, painless, right-sided abdominal mass. Laboratory values, including tumor markers α-fetoprotein and β-human chorionic gonadotropin, were within normal limits. Diagnostic imaging, including abdominal ultrasound, computed tomographic scan, and magnetic resonance imaging, suggested a large retroperitoneal mass consistent with a teratoma. Because the mass was thought to be arising from the retroperitoneum, an abdominal approach was chosen. After adequate exposure, it became clear that the tumor was arising from above the diaphragm. The diaphragm was incised, and the pleural cavity was entered. The tumor was found in the retropleural space where it was dissected away from the inferior vena cava, aorta, and chest wall. The patient recovered without complications.

RESULTS

Histologic examination revealed a mature cystic teratoma with no malignant features. The patient has been disease-free at 7-year follow-up, based upon both clinical examination and diagnostic imaging.

CONCLUSION

This is the first case report of a teratoma arising from the retropleural space. Preoperative imaging may be inaccurate for guiding surgical planning because the diaphragm may not be clearly visualized with current diagnostic techniques. Surgeons should be cautious regarding the location of tumors that arise near the diaphragm and should plan surgical resection carefully.

Mediastinal teratoma with malignant degeneration

Here, we report the case of a patient with a slowly-progressing anterior mediastinal teratoma submitted to surgical resection. The anatomopathological examination of the sample revealed malignant degeneration to carcinoid tumor. Such evolution is very rare, and we have found only three related studies in the literature. We describe the clinicopathological features of the tumor and discuss the treatment administered. The evolution was satisfactory, and the patient was submitted to oncological treatment.

Mediastinal tumors: a clinicopathological analysis

Between January 1993 and June 2003, 106 patients underwent surgical treatment of a mediastinal mass. Ages ranged from 6 months to 62 years, with peak incidence in the third and fourth decade of life (56%). The male to female ratio was 1.9:1. The anterosuperior mediastinum was involved in 76 patients (72%), middle mediastinum in 13 (12%), and posterior mediastinum in 17 (16%). Myasthenia gravis was present in 27% of cases. Complete surgical excision was possible in 68% of patients. Histopathologically, 41 (39%) patients had thymic pathology, 31 (29%) had lymphoma, 14 (13%) had germ cell tumors, 12 (11%) had neurofibroma, 4 (4%) had ganglioneuroma, 2 (2%) had bronchogenic cyst, and 1 each had thymic cyst and mesothelioma. The overall mortality was 3.8%.

Poor outcomes in patients with primary malignant mediastinal germ-cell tumors

Primary mediastinal germ-cell tumors (GCTs) without gonadal involvement are rare and can be divided into benign mature teratoma and malignant seminoma or nonseminoma. We describe our experience of malignant mediastinal GCTs and compare the presentations and outcome with those of benign teratomas. Four malignant GCTs (1 seminoma, 1 choriocarcinoma, and 2 yolk-sac tumors) have been treated in our hospital. All patients were men with obvious symptoms before diagnosis. The patient with seminoma was treated with surgery and radiation, while those with nonseminoma tumors were treated with chemotherapy and/or surgery. Two patients died, one with extended pulmonary metastasis and the other with relapsed disease and high levels of tumor markers. Compared with the nine cases of benign teratomas, the four malignant GCTs showed overwhelming male dominance, advanced symptoms at presentation, and poor outcome. These cases highlight the important role of disease staging and tumor-marker levels in malignant GCTs, and suggest that new treatment strategies for malignant GCTs await further investigation.

Primary Germ Cell Tumors of the Mediastinum: 10 Years of Experience in a Tertiary Teaching Hospital

Germ cell tumors occur mostly in the gonad. Extragonadal germ cell tumors are rare, and most occur in the retroperitoneum and mediastinum. Primary mediastinal germ cell tumors are often found in the anterior portion of the mediastinum and include teratomas and non-teratomatous tumors. Non-teratomatous tumors include seminomas and malignant non-seminomatous germ cell tumors (MNSGCTs). MNSGCTs include yolk sac tumors, choriocarcinomas, embryonal carcinomas, and mixed type germ cell tumors. Teratomas are the most common germ cell tumors of the mediastinum, and seminomas are the most common non-teratomatous germ cell tumors of the mediastinum. Cases of primary mediastinal MNSGCT reported in the literature are rare. In this report, we review all primary mediastinal germ cell tumors from a 10-year period at the Chung-Ho Memorial Hospital of Kaohsiung Medical University. A total of 14 cases were reviewed, including 11 patients with mature teratomas, two with yolk sac tumors, and one with seminoma. We discuss the differences in clinical presentation, histopathologic characteristics, treatment, and prognosis.

Management of Primary Malignant Germ Cell Tumor of the Mediastinum

BACKGROUND

Primary mediastinal malignant germ cell tumors (GCTs) are rare and have a worse prognosis than their gonadal counterparts. Although multimodality treatment is a standard therapeutic strategy in mediastinal GCTs, the clinical implications of surgical intervention remain unclear.

METHODS

Forty-eight patients with primary mediastinal malignant GCT who were treated at the National Cancer Center Hospital, Tokyo, from 1962 to 2002 were studied retrospectively with regard to their histology and clinical profile.

RESULTS

Mediastinal GCT occurred predominantly in young males, with a mean age of 28.8 years at the time of diagnosis. There were 46 males (96%) and two females (4%). Histologically, seven patients (15%) were diagnosed as having pure seminoma and 41 (85%) had non-seminomatous GCT. Treatment consisted of surgery alone in nine patients, surgery followed by chemotherapy in two, and chemotherapy followed by surgery in 20. The other 17 patients received chemotherapy and/or radiotherapy without surgery. Of these latter 17 patients, 14 developed progressive disease and three were followed up with a sustained partial response. Among the 31 patients who underwent surgery, complete resection was performed in 27 (87%) and incomplete resection was performed in four (13%). Twelve (41%) patients had elevated serum tumor marker levels preoperatively. Among the 20 patients who received preoperative chemotherapy, viable cells were found in the resected specimen in six (30%). With regard to tumor recurrence in patients with surgical intervention, the preoperative serum tumor marker levels and the presence of viable cells in the resected specimen were significantly associated with recurrence. There was no significant association between surgical curability and recurrence. The 5-year overall survival rate in all 48 patients was 45.5%.

CONCLUSIONS

Surgical intervention for mediastinal GCT may be needed to remove a chemotherapy-refractory tumor or to assess the pathological response to chemotherapy to determine the indications for further chemotherapy.

Primary germ cell tumors in the mediastinum: a 50-year experience at a single Japanese institution

BACKGROUND

Primary germ cell tumors (GCT) of the mediastinum share similar clinical and biologic characteristics, which are different from their testicular counterpart. The purpose of the current study was to review the authors' institutional experience of mediastinal GCT, emphasizing the clinical spectrum, time trends of treatment, and recent advances in therapeutic modalities for malignant GCT.

METHODS

Between 1951 and 2000, 129 patients (70 males and 59 females) underwent surgical treatment for GCT, which accounted for 16.0% of the mediastinal tumors during the same period. There were 95 patients with mature teratomas, 13 patients with seminomas, and 21 patients with nonseminomatous germ cell tumors (NSGCT) with median ages of 26.4 years, 27.6 years, and 28.5 years, respectively.

RESULTS

Adult patients with mature teratomas were less symptomatic (33.3%) than pediatric patients (52.4%). All patients with mature teratoma were cured by resection alone. Eight of the 13 patients (61.5%) with seminoma were symptomatic and 10 of 13 patients (83.3%) survived after surgery and radiation with/without chemotherapy. Nineteen of 21 patients (90.5%) with NSGCT had dyspnea, chest pain, and superior vena cava syndrome. Before 1985, patients received radical resection and/or chemoradiotherapy. However, all patients died due to disease progression, with a median survival period of 7.6 months. After 1986, six of eight patients received cisplatin-based chemotherapy, including three who received additional high-dose chemotherapy with a supporting peripheral blood stem cell transplantation until tumor markers normalized. Five patients who underwent salvage resection are currently disease free with a median survival period of 58.3 months.

CONCLUSIONS

The institutional experience indicates the benign nature of mediastinal mature teratomas and the excellent prognosis for patients with seminomas after resection. An improved survival advantage was ensured with cisplatin-based preoperative chemotherapy in patients with NSGCT.

Diagnosis, staging, and clinical characteristics of the patient with mediastinal germ cell carcinoma

When an anterior mediastinal mass is found in a young male patient, mediastinal germ cell tumors should always be one of the leading diagnostic considerations. The staging evaluation and diagnostic procedures should be performed rapidly. Every patient with a mediastinal germ cell tumor should be approached with curative intent, and appropriate treatment should be initiated as soon as the brief diagnostic procedure has been completed. Currently, treatment is curative in most patients (> 80%) with pure mediastinal seminoma, even in patients with huge mediastinal tumors and evidence of distant metastases. Although the cure rate is lower for patients with nonseminomatous germ cell tumors, the overall cure rate of 35% to 40% makes these tumors one of the most effectively treated advanced cancers. Further details regarding the treatment of mediastinal germ cell tumors are presented elsewhere in this issue.

Intensive chemotherapy and radical resections for primary nonseminomatous mediastinal germ cell tumors

BACKGROUND

Primary nonseminomatous germ cell tumors of the mediastinum (PNSGM), unlike malignancies of gonadal origin, have a poor prognosis. We report a single institutional experience over a 5-year period of PNSGM treated with intensive chemotherapy, followed by radical operation in those who responded to this neoadjuvant regimen.

METHODS

From 1993 to 1998, 20 patients were referred for the management of PNSGM. All were male, with a median age of 30.5 years (range 18 to 48). Eighteen of 20 (90%) presented with symptoms. Most tumors were large, with a median diameter of 10 cm (range 3 to 20 cm). Thirteen patients (65%) had metastatic disease at the time of presentation. Eleven patients had received no prior treatment (initial group) and 9 were referred for salvage therapy after progression of their tumors, following treatment at other facilities (salvage group). All had elevated serum tumor markers (beta hCG and alpha-fetoprotein). Preoperative chemotherapy included alternating cycles of combinations of 3 or more drugs, including cisplatin, bleomycin, etoposide, vincristine, methotrexate, actinomycin, cyclophosphamide, and doxorubicin. An average of 10 cycles of chemotherapy was given to each patient in the initial group, and six to those in the salvage group. Five patients (25%) developed transient renal insufficiency, and 35% developed pulmonary infiltrates related to bleomycin. There were 3 chemotherapy related deaths.

RESULTS

After chemotherapy, 11 patients underwent operation, with 10 complete resections of the residual mediastinal tumors. There were no perioperative deaths. The 2-year survival in the initial group is 72%, and 42% for the salvage group.

CONCLUSIONS

An aggressive, multidisciplinary approach of alternating cycles of chemotherapy, followed by complete surgical resection of all remaining disease in patients whose markers normalize, can be associated with prolonged survival in patients with PNSGM.

Teratoma with malignant transformation in the anterior mediastinum: a case report

Malignant transformation of teratoma in the anterior mediastinum is rare; the mass usually has a long history and is seen in older patients. We report a case of teratoma with malignant transformation in the anterior mediastinum, complicated by rupture. CT revealed a lobulated, inhomogeneous cystic mass with a fat component and wall calcifications. The lateral wall was disrupted and consolidation in the adjacent left upper lobe was noted, suggesting rupture. A heterogeneously enhanced solid portion, obliterating the fat plane between the mass and the great vessels was present in the medial aspect of the mass, and pathologic examination demonstrated the presence of adenocarcinoma.

Occurrence of malignant non-germ cell components in primary mediastinal germ cell tumours

METHODS

Thirty-five patients with primary mediastinal germ cell tumours (PMGCT) underwent primary thoracotomy in a 30-year period (1965-1994). Of the 35 patients, 12 had benign teratomas, five pure seminomas and 18 non-seminomatous germ cell tumours.

RESULTS

Out of 18 non-seminomatous germ cell tumours, 14 comprised more than one malignant component. In two cases malignant teratomas had an additional malignant non-germ cell component: one a mixed sarcomatous component and the other a neuroendocrinal component. There were different methods of treatment between 1965 and 1994. All but one of patients with seminomas survived for 5 years. Among 18 patients with malignant PMGCT, all but two died within 5 years (mean survival rate was 15 months).

CONCLUSIONS

When planning treatment of patients with malignant PMGCT we have to take into account the fact that malignant non-germ-cell components may occur. In this circumstances, surgical resection after initial chemotherapy is recommended.

[Precocious puberty secondary to an intramedullary germinoma]

BACKGROUND

hCG secreting tumors are responsible for 21% of precocious puberties in boys. Usual localizations are hepatic, cerebral, mediastinal and gonadic.

CASE REPORT

A 4-year-old boy developed precocious puberty with rapid evolution. Serum beta hCG suggested germinal etiology, but radiological procedures failed to find any usual localization. Further occurrence of pain in the legs led to carry out a lumbar puncture. The high cerebrospinal fluid/blood gradient of beta hCG suggested the presence of an intramedullar tumor. Medullar magnetic resonance imaging found a large tumor facing L1 and L2.

CONCLUSION

To our knowledge, this localization is described for only the second time.

Primary seminoma in the middle mediastinum: case report in a 69-year-old male

Primary mediastinal seminoma is an uncommon tumor usually located in the anterior mediastinum. The majority of cases occur in young males. We report here an extremely rare case of a 69-year-old male with primary seminoma in the middle mediastinum. The patient had no complaints, but an abnormal shadow was seen in a routine chest X-ray. We performed a tumorectomy in the middle mediastinum, a thymectomy and an orchidectomy and added postoperative chemotherapy. It seems that the tumor was not associated with the thymus, so we believe the tumor did not stem from the embryonic thymus. Our case demonstrated that mediastinal seminoma does not always occur in the anterior mediastinum of young males. Although this case is rare, seminoma should be included among the possible diagnoses of a middle mediastinal mass.

Initial management of primary mediastinal seminoma: radiotherapy or cisplatin-based chemotherapy?

Primary mediastinal seminoma is an uncommon neoplasm, the optimal management of which is still debated. Radiotherapy produces a 65% disease-free survival rate. We assess whether these results have been improved with the advent of cisplatin-based chemotherapy. Data from 14 patients treated at the Institut Gustave-Roussy were reviewed. 9 had received cisplatin-based chemotherapy (Group 1): their outcome was compared with that of 5 patients treated with radiotherapy without chemotherapy (Group 2). We also reviewed data from the English literature using strict criteria, and report results concerning patients who received cisplatin-based chemotherapy and those who received radiotherapy. 8 of the 9 patients (89%) in Group 1 are long-term disease-free survivors and only 3 of 5 patients in Group 2. The patient who died in Group 1 was the only one who refused surgical resection of residual masses after chemotherapy. The review of the literature revealed that 59 of 68 (87%) patients initially managed with cisplatin- or carboplatin-based chemotherapy and for whom sufficient data are available, are long-term survivors and free of disease. Some of these patients had also received radiotherapy. Only 64 of 103 (62%) treated with thoracic radiotherapy without chemotherapy were long-term disease-free survivors. The disease-free survival rate of 51 patients who received cisplatin-based chemotherapy (excluding those who received carboplatin) was 86%. The difference in survival between patients administered cisplatin-based chemotherapy and those who underwent radiotherapy is apparently not due to unbalanced prognostic factors, the effect of time or non-specific medical management. We conclude that cisplatin-based chemotherapy allows long-term disease-free survival in approximately 85% of patients. These results seem to be higher than those obtained without cisplatin-based chemotherapy. However, a randomised study is required for definitive conclusions, but it is very unlikely that such a study will be performed due to the rarity of this neoplasm. Another alternative would be a meta-analysis based on individual data.

Primary mediastinal choriocarcinomas: a clinicopathologic and immunohistochemical study of eight cases

Primary choriocarcinoma of the anterior mediastinum is by far the rarest and most controversial form of extragonadal germ cell tumor. A clinicopathologic study of eight primary mediastinal neoplasms bearing the histopathologic and immunohistochemical features of choriocarcinoma is presented. The patients were all men between the ages of 21 and 63 years (mean, 42 years). Clinical symptoms included shortness of breath, chest pain, cough, and superior vena cava syndrome; one patient also had gynecomastia. All patients presented with large anterior mediastinal masses on chest radiographs that measured an average of 10 cm in greatest diameter. Grossly, the tumors were described as large, soft, extensively hemorrhagic, and with foci of necrosis. Histologically, they were characterized by a dual cell population composed of cytotrophoblastic cells with uniform, round nuclei, clear cytoplasm, and prominent nucleoli admixed with large, multinucleated syncytiotrophoblastic cells with bizarre nuclei, prominent nucleoli, and abundant eosinophilic cytoplasm. Immunohistochemically, the tumors were notable for strong keratin and beta-human chorionic gonadotropin (HCG) positivity. Seven patients presented at the time of diagnosis with thoracic and extrathoracic (liver, adrenal, kidney, and spleen) metastases. In one case, the tumor was entirely confined to the mediastinum. All patients died over a period of 1 to 2 months. Complete autopsies were performed in all cases; none of the patients showed evidence of a testicular tumor or scar after thorough examination of the testes on serial sectioning. The present cases demonstrate the widespread distribution of germ cells in the human body and lend further support to the existence of primary extragonadal choriocarcinoma arising in the thymic region.

Primary germ cell tumors of the mediastinum: II. Mediastinal seminomas--a clinicopathologic and immunohistochemical study of 120 cases

BACKGROUND

Primary seminomas of the mediastinum are unusual neoplasms that are morphologically indistinguishable from their gonadal counterparts but may have different biologic behavior because they arise at this particular location.

METHODS

The clinical and pathologic features in 120 cases of primary mediastinal seminoma were reviewed, and the immunohistochemical staining patterns in 50 of these tumors were also analyzed.

RESULTS

The patients were all men between the ages of 14 and 79 years (mean age, 46.5 years). Their clinical symptoms included cough, chest pain, and dyspnea. In some patients, the lesions were asymptomatic and discovered incidentally on routine chest radiographs. None of the patients had a previous history of testicular neoplasm or tumor elsewhere. Macroscopically, the tumors were described as soft and tan, with a slightly lobulated cut surface, and measured up to 16 cm in greatest dimension. Histologically, the morphologic features were similar to those of tumors occurring in the gonads, namely, a neoplastic proliferation of round-to-polygonal cells with indistinct cell borders, clear-to-lightly-eosinophilic cytoplasm with round-to-oval nuclei and prominent nucleoli, associated with a prominent inflammatory background composed mainly of mature lymphocytes. Necrosis, hemorrhage, multinucleated giant cells, granulomatous reaction, and remnants of thymic tissue were observed in a variable number of cases; mitoses were rare. Immunohistochemical studies in 50 cases showed cytoplasmic staining with placental alkaline phosphatase in 80% of the tumors, focal dotlike positivity for CAM 5.2 low-molecular-weight keratins in 75%, focal cytoplasmic staining for wide-spectrum keratin in 70%, focal positive reaction with vimentin in 70%, and focal positivity with HCG in singly scattered cells in 5%. Immunostains for carcinoembryonic antigen, epithelial membrane antigen, and alpha-fetoprotein were negative in all the cases studied. Fifty patients were Stage I, 3 patients were Stage II, and 12 patients were Stage III. Clinical follow-up information was obtained for 65 cases (54%). Forty-nine patients were alive and disease free after a period ranging from 1 to 19 years (mean follow-up, 10 years). Sixteen patients died within the same period and were found to have metastases to distant organs. Of the 16 patients who died, 6 showed extension of the tumor outside of the mediastinal compartment at the time of initial diagnosis (Stage III lesions). Aside from clinical staging, the authors' findings also suggest that patients >37 years have worse outcomes than younger individuals. The authors were unable to find any correlation between histopathologic features and clinical behavior in any of these cases.

CONCLUSIONS

Clinical and pathologic staging of mediastinal seminomas are important parameters that can be useful in determining the clinical outcomes of patients with these tumors. Tumor invasion into adjacent organs represents a marker of increased morbidity and mortality. The authors' findings suggest that patients with mediastinal seminomas may have a very good prognosis when the diagnosis is made early; patients with more advanced lesions may require more aggressive therapy for improved local control and prevention of distant metastases.

Primary mediastinal tumors. Part 1: tumors of the anterior mediastinum

Primary anterior mediastinal neoplasms comprise a diverse group of tumors and account for 50% of all mediastinal masses. Thymomas are most common and can be locally invasive and associated with parathymic syndromes. Thymic carcinomas and thymic carcinoids are rare malignancies with a propensity for local invasion and distant metastases. Thymolipomas are benign thymic tumors. The mediastinal germ cell tumors are a heterogeneous group of benign and malignant neoplasms. Mediastinal lymphangiomas are rare tumors and predominantly occur in young children. In contrast, mediastinal goiters are relatively common in adults. Mediastinal parathyroid adenomas are an uncommon cause of persistent hyperparathyroidism and rarely cause a discernible mass. The clinical, radiologic, and therapeutic aspects of the most common masses are reviewed.

Goblet cell carcinoid arising in a mature teratoma of the mediastinum

Goblet cell carcinoid (GCC) is a rare but distinctive neoplasm with features of both adenocarcinoma and carcinoid tumor. Most cases described in the literature have occurred in the appendix. An additional well-defined location is the ovary, and these tumors have been associated with a mature teratoma of the ovary. GCC arising within a mature teratoma of the mediastinum has not been described in the English-language literature. We report a case of this previously undescribed entity and provide a review of the literature on mediastinal teratomas with malignant transformation. The histologic findings included uniform, smooth-bordered glandular nests lined by goblet cells and admixed endocrine and Paneth cells. Occasional tubular glands were present, as were transitional type glands with both goblet cell and tubular features. Cytologic atypia was minimal, and mitotic activity was rare. Immunohistochemical studies showed positive staining of GCC tumor cells with chromogranin, cytokeratin, neuron-specific enolase, serotonin (focal), and Leu-7 (focal). The GCC component was entirely contained within the mature teratoma.

Primary mediastinal malignant germ cell tumour. Single institution experience in Chinese patients and correlation with specific alpha-fetoprotein bends

Ten Chinese patients were reviewed, all with mediastinal germ cell tumours and treated in our centre during the past 8 years. Three patients with pure seminomas were given chemotherapy with or without radiotherapy. AB achieved complete remission with no relapse. Seven patients with non-seminomatous germ cell tumours (NSGCT) were given chemotherapy, with or without surgery. Two patients with rapid decay of alpha-fetoprotein (AFP) levels (half-life less than or equal to 7.2 days) during chemotherapy achieved complete remission with no relapse. Five patients with prolonged decay of AFP levels (half-life > 7.2 days) failed to achieve complete remission with initial chemotherapy and all but one patient died between 5 and 9 months later. One patient developed acute megakaryocytic leukaemia. Using isoelectric focusing, AFP bands specific to NSGCT were quantified, and comparison was made with the total AFP in five cases. In each case the change in NSGCT-specific AFP concentration in response to therapy closely paralleled that of total AFP. Estimation of NSGCT-specific AFP offers no apparent advantage in monitoring disease response or progression.