Germ Cell Tumors With Sarcomatous Components

Mark Wick contributions to pathology of the mediastinum

Mark Wick made a wide range of contributions to the field of mediastinal pathology. Early papers amplified the spectrum of neuroendocrine carcinomas of the thymus and brought attention to the aggressive nature of this tumor, also highlighting the occurrence of coexisting carcinoid tumor and small cell carcinoma of this organ. The controversial issue of thymoma classification was addressed in several papers and editorial comments, while also reporting a case of metastatic thymoma. A series of thymic carcinomas as well a report on the unusual clear cell variant bear his name as one of the authors. He summarized the topic of mediastinal cyst in a review published in 2005. Sarcomas arising in mediastinal germ cell tumors were also within the purview of his interests, with a publication of series of seven cases. He reviewed the topic of inflammatory myofibroblastic tumor of the heart and added a case to the existing literature. Two books dedicated to different aspect of mediastinal pathology also carry his name in the front cover in association with Drs Taazelar in one and Marchevsky in the other.

Primary germ cell tumours of the mediastinum: A review with emphasis on diagnostic challenges

This article will review current aspects of the histopathological, immunohistochemical and molecular analysis of primary mediastinal germ cell tumours (PMGCTs) as well as their aetiological, epidemiological, clinical and therapeutic features. PMGCTs represent an important differential diagnosis in the spectrum of mediastinal tumours, and their diagnosis is usually made on small tissue samples from core needle biopsies in combination with diagnostic imaging and serum tumour markers. As in lymphomas, a small biopsy is often the only viable tumour sample available from these patients, as they receive chemotherapy prior to eventual surgical resection. Pathologists therefore need to apply an efficient combination of immunohistochemical markers to confirm the diagnosis of a PMGCT and to exclude morphological mimics.

Resection of a Large Growing Mediastinal Germ Cell Tumor Using a Multidisciplinary Approach

Mediastinal germ cell tumors (GCTs) are rare. Post-chemotherapy residual masses in patients with a nonseminomatous GCT require resection. A patient with a large mediastinal GCT involving the left subclavian artery, superior vena cava (SVC) and hilum of the right lung is presented. Despite a biochemical response to chemotherapy, the tumor enlarged on serial imaging. With guidance from medical oncology, a multidisciplinary surgical team, including cardiac anesthesia, cardiac surgery and thoracic surgery resected the tumor with a staged reconstruction of the SVC. The procedure was well tolerated and yielded clear margins. The final pathology showed a significant associated component of rhabdomyosarcoma.

Surgical resection in patient with teratoma with somatic-type malignancy transformed into rhabdomyosarcoma resulted in long-term survival

Introduction

Testicular germ cell tumors with somatic-type malignancy, wherein teratomas transform into sarcomas, is drug resistant and has a poor prognosis.

Case presentation

A 43-year-old man presented with a left testicular tumor, multiple pulmonary metastases, and mediastinal and para-aortic lymph node metastases. The testicular tumors were diagnosed as germ cell tumors. After bleomycin, etoposide, and cisplatin chemotherapy; right upper lobectomy for the pulmonary metastasis; and paclitaxel, ifosfamide, and cisplatin chemotherapy, rapidly progressing mediastinal lymph node metastasis was observed. It was resected at another specialized center owing to the challenging surgical approach. The histopathological diagnosis of the resected tumor was a teratoma with somatic-type malignancy (rhabdomyosarcoma). Subsequently, left hilar lymph node metastasectomy and left upper lobectomy were performed for the pulmonary metastases. The patient survived for more than 8 years after initial treatment.

Conclusion

Surgery, although challenging, may yield long-term survival for patients with testicular germ cell tumors with sarcomatous transformation.

First report of primary testicular leiomyosarcoma in two dogs

BACKGROUND

Testicular tumours are common in dogs and, among them, interstitial cell tumours, seminomas and sustentacular cell tumours are the most reported. Mesenchymal testicular tumours are rarely reported in humans as in veterinary medicine where only three cases of sarcomas (leiomyomas and leomyosarcomas) have been described in two stallions and in a ram.

CASE PRESENTATION

The present cases regarded a 12-year-old mixed-breed dog and a 10-year-old American Staffordshire Terrier that underwent bilateral orchiectomy. Formalin fixed testes were referred for histopathological diagnosis. At gross examination, in one of the testes of both dogs, a white, firm and variably cystic testicular mass, effacing and replacing the testicular parenchyma was detected. Samples were collected from both neoplastic and contralateral testes, routinely processed for histology and serial sections were also examined immunohistochemically with primary antibodies against cytokeratins, vimentin, Von Willebrand factor, inhibin-α, α-smooth muscle actin, smooth muscle myosin and desmin. Histopathological features as well as the immunohistochemical results, positive for vimentin, actin, myosin and desmin, confirmed the mesenchymal origin and the myoid phenotype of both testicular tumours supporting the diagnoses of leiomyosarcoma.

CONCLUSIONS

To the authors knowledge these are the first cases of primary testicular sarcoma reported in the canine species. However, even rare, these tumours deserve to be considered in routine diagnosis when a testicular spindle cell tumour is observed. The immunohistochemical panel applied was useful to distinguish the present tumours from undifferentiated Sertoli cell tumours confirming the diagnosis of leiomyosarcoma.

Reprint of: somatic-type malignancies in testicular germ cell tumors

The development of somatic-type malignancy (SM) in testicular germ cell tumor represents a major challenge in the diagnosis and treatment of testicular cancer. Most SMs are derived from teratoma, and the remainder is associated with yolk sac tumor. They occur more frequently in metastases than in primary testicular tumors. SMs demonstrate a variety of histologic types, including sarcoma, carcinoma, embryonic-type neuroectodermal tumor, nephroblastoma-like tumor, and hematologic malignancy. Sarcoma, particularly rhabdomyosarcoma, accounts for the majority of SMs in the primary testicular tumors, whereas carcinoma, particularly adenocarcinoma, is the most common SM in metastases. Although SMs derived from testicular germ cell tumors mimic their histologic counterparts in other organs with overlapping immunohistochemical profiles, isochromosome 12p is present in most SMs, which can be useful in the differential diagnosis. The presence of SM in the primary testicular tumor may not worsen the outcome, but the development of SM in metastasis is associated with a poor prognosis. Furthermore, somatic-type carcinoma is likely associated with a worse prognosis than somatic-type sarcoma. Although SMs respond poorly to the cisplatin-based chemotherapy, timely surgical resection is an effective treatment for most patients.

A case of mediastinal teratoma with malignant transformation into angiosarcoma and relapse with multiple bone metastases that was cured by a multidisciplinary treatment

Introduction

Complete resection is essential for the treatment of teratoma with malignant transformation, and if metastasis occurs, it will be difficult to cure. We report a case of primary mediastinal teratoma with differentiation into angiosarcoma that caused bone metastases but was cured by multidisciplinary treatment.

Case presentation

A 31-year-old man with a primary mediastinal germ cell tumor underwent primary chemotherapy followed by post-chemotherapy resection, with angiosarcoma due to malignant transformation found in the surgical specimen. Femoral diaphyseal metastasis was manifested, and he underwent femur curettage followed by radiation therapy of 60 Gy in parallel with 4 cycles of chemotherapy combining gemcitabine and docetaxel. Although thoracic vertebral bone metastasis emerged 5 months after treatment, intensity-modulated radiation therapy was successful, and metastatic lesions have remained shrunken for 39 months after treatment.

Conclusion

Even if complete resection is difficult, teratoma with malignant transformation may be cured by multidisciplinary treatment based on histopathology.

Tislelizumab immunotherapy combined with chemotherapy in the treatment of a patient with primary anterior mediastinal undifferentiated pleomorphic sarcoma with high PD-L1 expression: A case report and literature review

Undifferentiated pleomorphic sarcoma (UPS) is a rare and aggressive soft tissue tumor with a high degree of malignancy and rapid progression, usually occurring in the extremities, retroperitoneum, and abdomen, whereas it rarely arises in the mediastinum, and is treated mainly by surgical resection. The prognosis of patients with advanced sarcoma is poor, and doxorubicin monotherapy is the standard first-line chemotherapy for most advanced soft tissue sarcomas (STS), but the prognosis is generally unsatisfactory. Immune checkpoint inhibitors (ICIs) have been established as therapies for many solid cancers in recent years; however, evidence on the efficacy of ICIs in undifferentiated sarcoma is scarce, mostly consisting of small studies, and no ICIs are currently approved for use in sarcomas. We report a case of a middle-aged man with primary mediastinal UPS with high PD-L1 expression (TPS was approximately 80%) and TLS positive. The patient was treated with sequential tislelizumab monotherapy maintenance after 6 cycles of tislelizumab combined with epirubicin, efficacy evaluation was partial remission (PR), progression-free survival (PFS) was 8.5 months, and grade 1 fatigue was identified as an adverse event.

[Diagnostic problems in testicular tumours in consultant pathology : A practical guide]

The great variety of pathological patterns in germ cell tumours, especially in yolk sac tumours but also the possibility of somatic-type malignancies, can complicate daily diagnosis. For the correct diagnosis, knowledge of morphological aspects and additional immunohistochemical staining can be helpful. Also, rare entities like sex cord stromal tumours, tumours of testicular adnexa or mesenchymal tumours of the spermatic cord can be diagnostically challenging.

Primary immature teratoma in the liver with growing teratoma syndrome and gliomatosis peritonei: a rare case report

Background

Primary liver immature teratoma is extremely rare and only 4 cases have been reported, let alone with growing teratoma syndrome (GTS) and/or gliomatosis peritonei (GP).

Case presentation

Here, we report a case of a 44-year-old female presenting with progressive abdominal distension and elevated serum alpha fetal protein (AFP) level. CT/MRI scans revealed a large cystic-solid mass in the right lobe of the liver, accompanied with implant or metastasis in the abdominal cavity. Pathologic examination at biopsy suggested immature teratoma. After 4 cycles of chemotherapy, an MRI showed a slight increase in tumor size. Therefore, surgical resection of the right lobe of the liver was performed. The final histological diagnosis was a mature teratoma (tumor size 28 cm × 14 cm × 13 cm), with no residual immature component, and the diagnosis of GTS was considered. The patient continued to receive 2 courses of postoperative chemotherapy. An abdominal CT scan revealed innumerable miliary nodules in bilateral adnexal areas 2 months after surgery. Histologically, large numbers of mature glia were observed, supporting the diagnosis of GP.

Conclusions

We report for the first time a case of primary liver immature teratoma with GTS and GP in an adult. Longer follow-up is needed to assess definitive efficacy.

Updates in Pathology for Retroperitoneal Soft Tissue Sarcoma

Retroperitoneal tumors are extremely rare. More than 70% of primary retroperitoneal soft tissue tumors are malignant. The most common sarcomas in the retroperitoneum include liposarcomas and leiomyosarcoma, however other sarcomas, along with benign mesenchymal tumors, can occur. Sarcomas are a heterogenous group of tumors with overlapping microscopic features, posing a diagnostic challenge for the pathologist. Correct tumor classification has become important for prognostication and the evolving targeted therapies for sarcoma subtypes. In this review, the pathology of retroperitoneal soft tissue sarcomas is discussed, which is important to the surgical oncologist. In addition, less common sarcomas and benign mesenchymal tumors of the retroperitoneum, which may mimic sarcoma clinically and pathologically, are also discussed.

Teratoma With Malignant Ectomesenchymoma in the Pineal Region: A Case Report

Tumors involving the pineal gland include germinomas, non-germinomatous, and parenchymal tumors. Sometimes these tumors can be differentiated into rhabdomyosarcoma, which is an aggressive and rapidly recurring sarcoma but is a rare event. We present the case of a 23-year-old male, with an eight-year-long history of a non-treated brain tumor compatible with a teratoma. Chemotherapy and radiotherapy were offered, and two years later, malignant transformation to astrocytoma, rhabdomyosarcoma, neural cell carcinoma, ganglioglioma, and low-grade chondrosarcoma was noted. Immunohistochemistry was valuable in differentiating these entities that confirmed the diagnosis. Malignant transformations may be secondary to the normal transformation of multipotent embryonic cells into more developed tissues after radiotherapy of teratoma and malignant ectomesenchymoma transformation.

Somatic-Type Malignancies in Testicular Germ Cell Tumors

The development of somatic-type malignancy (SM) in testicular germ cell tumor represents a major challenge in the diagnosis and treatment of testicular cancer. Most SMs are derived from teratoma, and the remainder is associated with yolk sac tumor. They occur more frequently in metastases than in primary testicular tumors. SMs demonstrate a variety of histologic types, including sarcoma, carcinoma, embryonic-type neuroectodermal tumor, nephroblastoma-like tumor, and hematologic malignancy. Sarcoma, particularly rhabdomyosarcoma, accounts for the majority of SMs in the primary testicular tumors, whereas carcinoma, particularly adenocarcinoma, is the most common SM in metastases. Although SMs derived from testicular germ cell tumors mimic their histologic counterparts in other organs with overlapping immunohistochemical profiles, isochromosome 12p is present in most SMs, which can be useful in the differential diagnosis. The presence of SM in the primary testicular tumor may not worsen the outcome, but the development of SM in metastasis is associated with a poor prognosis. Furthermore, somatic-type carcinoma is likely associated with a worse prognosis than somatic-type sarcoma. Although SMs respond poorly to the cisplatin-based chemotherapy, timely surgical resection is an effective treatment for most patients.

Germ cell tumors with neuroglial differentiation do not show molecular features akin to their central nervous system counterpart: experience from extra-gynecological sites

Teratomas with secondary somatic malignancy showing neuroglial differentiation (central nervous system (CNS)-type tumors) arising from a glial or neuroepithelial component is a very uncommon event and primarily described in the ovary. We aimed to describe the morphological spectrum and molecular features of CNS type of neuroepithelial tumors arising from the germ cell tumors (GCT) in the extra-gynecological sites. All cases of teratoma and mixed GCT arising from the non-gynecological sites over 7 years were screened for CNS type of neuroepithelial tumors. Detailed histological and immunohistochemical analysis was performed. IDH1 and 2 sequencings were performed in the glial tumors. Fluorescent in situ hybridization (FISH) was performed for EWSR1 rearrangement, 19/19q co-deletion, CDKN2A homozygous deletion, EGFR amplification, and C19MC amplification, wherever required. Out of 302 GCTs examined, the neuroglial tumor was detected in 15 cases. It included nine cases of glial tumors (including one pilocytic astrocytoma (grade I), two diffuse astrocytomas (grade II), one oligodendroglioma (grade II), one gemistocytic astrocytoma (grade II), three anaplastic astrocytomas (grade III), and one case of glioblastoma (grade IV)) and six cases of the embryonal tumor with multilayered rosettes (ETMR). None of the gliomas showed IDH mutation by immunohistochemistry or sequencing. The ETMR cases did not show Lin28 expression or C19MC amplification. To conclude, the spectrum of neuroglial tumors arising from teratoma in the extragonadal sites is vast and most commonly includes glial neoplasms and embryonal tumors. Our findings indicate that the genotype and pathogenesis of tumors with neuroglial differentiation in teratoma are distinct from their CNS counterpart.

Survival Outcomes of Patients With Primary Mediastinal Germ Cell Tumors: A Retrospective Single-institutional Experience

BACKGROUND/AIM

Primary mediastinal non-seminomatous germ cell tumors (PMNSGCTs) are occasionally complicated by a hematologic malignancy, as with somatic-type malignant tumors called germ cell tumors with somatic-type malignancy (GCTSTM) and are known to have a poor prognosis.

PATIENTS AND METHODS

Data obtained between September 1997 and February 2020 for patients with mediastinal germ cell tumor at our institution were retrospectively analyzed. Key outcome measures included survival rates and the clinical features of non-seminoma cases.

RESULTS

Of 16 patients, 9 had pure seminoma, and 7 had non-seminoma. At the median follow-up of 56.2 months, the 5-year survival rate was significantly higher in patients with seminoma (100%) than in those with non-seminoma (37%) (log-rank test, p=0.0153). Regarding PMNSGCT, two patients evolved into GCTSTM and three had concomitant hematological malignancies.

CONCLUSION

Patients with PMNSGCTs, GCTSTM complications, and hematologic malignancies showed poor survival, suggesting the need for the development of treatment strategies.

Malignant Gonadal Germ Cell Tumors (Other Than Pure Germinoma) in Patients With Disorders of Sex Development: A Report of 21 Cases Based Largely on the Collection of Dr Robert E. Scully, Illustrating a High Frequency of Yolk Sac Tumor With Prominent Hepatoid and Glandular Features

We describe 21 nonpure germinomatous gonadal germ cell tumors (9 with a germinoma component), all but 1 associated with gonadoblastoma, in patients with disorders of sex development who ranged from 7 to 36 years old (average, 20 y). Twenty patients were clinically described as phenotypic females with ambiguous genitalia/virilization and primary amenorrhea. The most common documented peripheral karyotype was 46,XY (10/12; 83%). Fifteen of 16 tumors with available clinicopathologic data were unilateral. They ranged from 7 to 30 cm (mean, 15.5 cm) and were solid and cystic with frequent necrosis and hemorrhage. Gonadoblastoma, in its classic (70%), dissecting (5%), or combined (25%) forms, was identified in all but 1. The malignant germ cell tumors were typically mixed except for 5 pure yolk sac tumors and 1 expansile gonadoblastoma with syncytiotrophoblast cells. When admixed, the most common component was yolk sac tumor (n=10), followed by germinoma (n=9), embryonal carcinoma (n=5), choriocarcinoma (n=4), immature teratoma (n=3), and teratoma (n=2). Typical morphologic patterns of yolk sac neoplasia, including reticular/microcystic, solid (including blastema-like), and endodermal sinus (Schiller-Duval bodies), were seen, as well as glandular (n=10) and hepatoid (n=6) differentiation, with cystically dilated glands and diffuse hepatoid morphology in 3 and 2 tumors, respectively. Two yolk sac tumors showed a sarcomatoid pattern. Somatic-type malignancies (alveolar rhabdomyosarcoma and low-grade spindle cell sarcoma, not otherwise specified) were identified in 1 case each. This is the first large series of germ cell tumors other than typical pure germinoma associated with gonadoblastoma. The high frequency of yolk sac tumor with glandular (especially cystic glandular) and hepatoid morphologies is noteworthy, and their presence should prompt further evaluation for an associated gonadoblastoma and possible disorder of sex development.

Morphological spectrum and molecular features of somatic malignant transformation in germ cell tumours

AIMS

Somatic malignant transformation (SMT) arising in germ cell tumours (GCTs) is an infrequent, but clinically relevant event. There is only limited knowledge on the morphological spectrum of SMT, and therapeutic management of these patients is poorly defined. In this work we revisit two consecutive case series (n=756) of GCTs. Clinicopathological data of SMT arising in GCT were determined, with focus on the histopathological spectrum, and molecular aspects were obtained by Fluorescence in situ Hybridization (FISH) and Next Generation Sequencing (NGS).

METHODS AND RESULTS

30 male patients (28 primary testicular, 2 primary extragonadal) were included. These patients represent 4% of GCT patients diagnosed in two institutes (University Hospital Zurich and IPO Porto). The most common SMT were adenocarcinoma (n=8), embryonic-type neuroectodermal tumours (ENETs, n=8) and rhabdomyosarcoma (n=6), but a wide range of challenging morphologies were depicted, including low-grade neuroglial tumour, adenosquamous carcinoma, neuroblastoma and neuroendocrine carcinoma. SMT was found in 15 primary tumour samples and in 27 metastatic samples of these 30 patients, the latter showing poorer overall-survival. Adenocarcinoma occurred only in metastasis post-chemotherapy and in one primary retroperitoneal GCT with SMT, but not in GCT of the testis. 12p gains were identified by FISH in all cases. NGS results were available in 6 patients. Clinical trials and/or targeted treatments based on the molecular profile of SMT were recommended in 4 patients.

CONCLUSIONS

SMT arising in GCTs represents a diagnostic challenge and should be confirmed by a specialized uropathologist. NGS based treatment recommendations may improve outcome of these patients.

Carcinosarcoma of the stomach: four cases that expand the morphologic spectrum of gastric cancer with a primitive phenotype

Carcinosarcoma of the stomach is a rare neoplasm characterized by the presence of both epithelial and mesenchymal malignant components. We describe four examples with a focus on the characterization of the epithelial components and the histogenetic implications for this unique tumor. All patients were men aged 40-79 years. All patients developed metastatic disease, and three of them died 4-19 months after the diagnosis. Sarcomatous elements included poorly differentiated spindle cell sarcoma without distinctive differentiation (n = 4), chondrosarcoma (n = 2), and rhabdomyosarcoma (n = 1). In two cases, the sarcomatous component was recognized only in metastatic lesions. Notably, carcinomatous components were characterized by multilineage and primitive cellular differentiation, including carcinoma with enteroblastic (n = 4), hepatoid (n = 3), yolk sac tumor-like (n = 1), trophoblastic (n = 1), and neuroendocrine (n = 1) differentiation, as well as conventional tubular adenocarcinoma (n = 4). On immunohistochemistry, all four cases showed varying degrees of positive expression of primitive phenotypic markers, including alpha-fetoprotein (AFP), glypican-3, or SALL4. All tumors showed mutant patterns of p53 staining, exhibiting either diffusely positive or completely negative staining. On the basis of these findings, at least some gastric carcinosarcomas are likely to be derived from carcinoma with a primitive phenotype, including AFP-producing adenocarcinoma. Our observations suggest that sarcomatous differentiation, as well as multilineage differentiation of epithelial components, may represent increased cellular plasticity of gastric carcinoma with a primitive phenotype.

Primary epithelioid angiosarcoma of the mediastinum, cytomorphologic features of a rare entity-A case report and literature review

Epithelioid angiosarcoma (EA) is a highly aggressive vascular neoplasm. Primary mediastinal EA is extremely rare with only few cases reported in the English literature. We herein present a case of a 78-year-old patient, who was found to have a right superior mediastinal mass associated with mediastinal and hilar lymphadenopathy. Endobronchial ultrasound guided fine needle aspiration cytology of a station 4R lymph node revealed a cellular, discohesive malignant neoplasm displaying primarily epithelioid morphology with occasional spindled, plasmacytoid, and tumor giant cells. The tumor cells had ample eosinophilic cytoplasm with pleomorphic nuclei and prominent nucleoli. Vasoformative features were noted, exemplified by widespread cytoplasmic vacuoles containing neutrophils and rare red blood cells (hemophagocytosis) and vascular channels identified solely in the cell block. By immunohistochemistry, the tumor cells stained strongly positive for vimentin, positive for ERG, CD-31, FLI-1, and focally positive for pan-cytokeratin. The cytomorphological features and immunostaining patterns were diagnostic of EA. No history of malignancy was reported, and no other lesions were identified on imaging. The diagnosis of primary mediastinal EA on cytology and small biopsy specimens may be challenging due to the rarity of this tumor, limited diagnostic material, and overlapping morphologic features with other entities in the differential diagnosis. A high index of suspicion, especially in cases with vasoformative features, and utilization of ancillary studies can help establish the diagnosis.

Somatic-type Malignancies in Testicular Germ Cell Tumors: A Clinicopathologic Study of 63 Cases

The development of somatic-type malignancies (SMs) in testicular germ cell tumors (GCTs) is a rare but well-recognized phenomenon. We studied the pathologic features of 63 GCTs with SMs in the testis (n=22) or metastases (n=41) and correlated these features with clinical outcomes. The patients with SMs in the testis (median age, 26 y) were younger than those with metastatic SMs (median age, 38.5 y). The SMs consisted of carcinomas (n=21), sarcomas (n=21), primitive neuroectodermal tumors (n=15), nephroblastomas (n=3), and mixed tumors (n=3). Sarcoma was the most common SM in the testis (n=11), and most sarcomas were rhabdomyosarcomas (n=9). Carcinoma was the most common SM in metastases (n=20), and most carcinomas were adenocarcinomas (n=12). In metastases, carcinomatous SMs developed after a longer interval from the initial orchiectomy (median times, 213 mo) than sarcomatous SMs (median times, 68 mo). Patients with metastatic SMs had significantly poorer overall survival than those with SMs in the testis (5-y survival rate, 35% vs. 87%; P=0.011). Furthermore, patients with carcinomatous SMs had a significantly worse prognosis than those with sarcomatous or primitive neuroectodermal tumor SMs (5-y survival rates, 17%, 77%, and 73%, respectively; P=0.002), when the whole cohort, including testicular and metastatic SMs, were analyzed. Our results demonstrate that SMs in metastatic GCTs are associated with a significantly worse prognosis than those in the testis. Furthermore, the histologic subtype of SM has a significant effect on the clinical outcome, with the carcinomatous SM carrying the highest risk for mortality.

Mediastinal Germ Cell Tumors: A Review and Update on Pathologic, Clinical, and Molecular Features

Mediastinal germ cell tumors (MGCTs) are the most common extragonadal germ cell tumors (GCTs) and most often arise in the anterior mediastinum with a male predilection. MGCTs also have a predilection for patients with Klinefelter syndrome and possibly other genetic conditions. MGCTs, as GCTs at other extragonadal sites, are thought to arise from germ cells improperly retained during migration along the midline during embryogenesis. Similar to their counterparts in the testes, MGCTs are classified into seminomatous and nonseminomatous GCTs. Seminomatous MGCT represents pure seminoma, whereas nonseminomatous MGCTs encompass pure yolk sac tumors, embryonal carcinoma, choriocarcinoma, mature or immature teratoma, and mixed GCTs with any combination of GCT types, including seminoma. Somatic-type or hematologic malignancies can also occur in association with a primary MGCT. MGCTs share molecular findings with GCTs at other sites, most commonly the presence of chromosome 12p gains and isochromosome i(12p). Treatment includes neoadjuvant chemotherapy followed by surgical resection of residual tumor, with the exception of benign teratomas, which require only surgical resection without chemotherapy. In this review, we highlight and provide an update on pathologic, clinical, and molecular features of MGCTs. Immunohistochemical profiles of each tumor type, as well as differential diagnostic considerations, are discussed.

Mesenchymal Tumors of the Mediastinum: An Update on Diagnostic Approach

Mesenchymal tumors of the mediastinum are a heterogenous group of rare tumors with divergent lineages. Mediastinal mesenchymal tumors are diagnostically challenging due to their diversity and morphologic overlap with nonmesenchymal lesions arising in the mediastinum. Accurate histologic diagnosis is critical for appropriate patient management and prognostication. Many mediastinal mesenchymal tumors affect distinct age groups or occur at specific mediastinal compartments. Neurogenic tumors, liposarcoma, solitary fibrous tumor, and synovial sarcoma are common mesenchymal tumors in the mediastinum. Herein, we provide an update on the diagnostic approach to mediastinal mesenchymal tumors and a review of the histologic features and differential diagnosis of common benign and malignant mesenchymal tumors of the mediastinum.

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.

Vasculogenic Mesenchymal Tumor: A Clinicopathologic and Molecular Study of 55 Cases of a Distinctive Neoplasm Originating From Mediastinal Yolk Sac Tumor and an Occasional Precursor to Angiosarcoma

We report 55 postchemotherapy resections of primary nonseminomatous mediastinal germ cell tumors with prominent vasculogenic features showing the formation of rudimentary to well-developed neoplastic vessels within primitive mesenchyme. These cases represented 25% of a cohort of 221 such specimens. The patients were 19 to 49 years old (mean, 28 y) and 98% had serological evidence of yolk sac tumor. The vasculogenic lesions, felt to represent a neoplastic reiteration of embryonic vasculogenesis in the splanchnic mesoderm of the yolk sac, were further subdivided into teratoma with vasculogenic stroma (n=9), vasculogenic mesenchymal tumor (VMT) (n=42, further classified into low grade [n=24] and high grade [n=18]), and angiosarcoma (n=4). The distinction of teratoma with vasculogenic stroma from VMT was based solely on the greater extent of VMT (exceeding 1 low power [×4 objective] microscopic field), with both categories showing a spectrum of vessels lined by atypical endothelium in a nonendothelial neoplastic stroma that often also generated vascular walls comprised of atypical smooth muscle. The angiosarcomas showed stratification of highly atypical endothelial cells or anastomosing vessels lined by nonstratified but cytologically similar endothelium. Immunohistochemical studies supported the generation of neoplastic vessels from the tumor stroma, most commonly by the development of stromal clefts showing reactivity for podoplanin, CD34, and occasionally ERG, followed by the gradual development from the clefts of thin-walled vessels that later became encircled by stromal cells showing smooth muscle differentiation by immunohistochemistry. Occasionally, round collections of stromal erythrocytes became surrounded by stromal cells to generate blood vessels. Fluorescence in situ hybridization showed chromosome 12p copy number increase in both the endothelial component and stromal component in 8/9 VMT cases and in 1/1 angiosarcoma. On follow-up, no patient with teratoma with vasculogenic stroma had evidence of a subsequent vascular tumor or sarcoma, whereas 8 of the 35 (23%) patients with VMTs (2 low grade and 6 high grade) and meaningful follow-up developed sarcoma (1 angiosarcoma, 2 rhabdomyosarcomas, and 5 not further characterized). The difference between low-grade and high-grade tumors was of borderline significance (P=0.058). Two of the 4 patients with angiosarcoma died of metastatic angiosarcoma, with the other 2 disease-free at 6.8 and 7 years. Compared with the 165 patients with follow-up and no vasculogenic lesions, there was a highly significant (P=4.3×10-5) association of any vasculogenic lesion with sarcomatoid tumors during the clinical course of VMT patients. In addition, 5/46 patients with follow-up and vasculogenic lesions (11%) died of either leukemia or myelodysplastic syndrome compared with 2 of 166 (1%) lacking them (P=0.0012). Three of the 5 patients had identifiable immature hematopoietic cells within their vasculogenic lesions, but 4 other VMT patients with these did not develop leukemia or myelodysplasia. We conclude: (1) vasculogenic lesions are frequent in postchemotherapy resections of primary mediastinal germ cell tumors with yolk sac tumor components; (2) they mostly consist of neoplastic vessels in a stroma that also generates neoplastic vascular walls of smooth muscle; (3) VMTs are associated with an increased incidence of sarcomas, even though most vasculogenic lesions in this context do not meet criteria for angiosarcoma; (4) the presence of vasculogenic lesions in postchemotherapy resections of primary mediastinal germ cell tumors place patients at increased risk for leukemia or myelodysplasia.

Case Report: The Complete Remission of a Mixed Germ Cell Tumor With Somatic Type Malignancy of Sarcoma Type With a GCT-Oriented Therapy: Clinical Findings and Genomic Profiling

Somatic malignant transformation in a germ cell tumor (GCT) is the development of non-germ malignancies; much of available literature refers to teratoma with malignant transformation (TMT). There are various transformation histologies such as sarcoma, adenocarcinoma, primitive neuroectodermal tumors, and more rarely carcinoid tumors, hemangioendothelioma, lymphoma, or nephroblastoma. The treatments of these entities include surgery and/or chemotherapy. A standard approach in choosing chemotherapy in TMT cases has not yet been established. Many authors suggest using chemotherapeutic agents based on the transformed histology, while others recommend GCT-oriented therapy combined with surgery as the primary treatment, reserving histology-driven chemotherapies for metastatic relapse. We report the clinical findings and the genomic profile of a mixed GCT case with somatic-type malignancy of sarcoma type. We achieved a complete radiological response with GCT-oriented chemotherapy performed as salvage therapy after sarcoma-histology therapy. In addition, molecular profiles with RNA-sequencing and exome sequencing analyses of the primary tumor and the tumor with somatic-type malignancy of sarcoma type were explored.

Treatment at an Inexperienced Center Suggests Worse Prognosis of Metastatic Germ Cell Tumors

BACKGROUND/AIM

We evaluated the clinical outcomes of patients with metastatic germ cell tumors (GCT) treated at our hospital, which belongs to a regional cancer center.

PATIENTS AND METHODS

Data pertaining to patients with metastatic GCT were obtained between April 2007-October 2017 and was retrospectively analyzed. Key outcome measures included objective response rates and survival rates.

RESULTS

All 42 patients received chemotherapy [complete response: eight (19.0%); partial response: 21 (50.0%); stable disease (SD): nine (21.4%); progressive disease: four patients (9.5%)]. Post-chemotherapeutic surgery was performed for seven out of 21 cases of partial response and two out of nine of stable disease. The 5-year survival rates of patients with good, intermediate and poor prognosis (International Germ Cell Consensus Classification) were 100%, 100%, and 71.4%, respectively. Patients who received induction chemotherapy at other hospitals had significantly poorer prognosis than those at our hospital (p=0.0043).

CONCLUSION

Patients with metastatic GCT should preferably receive chemotherapy at an experienced institution.

Durable response achieved using Pazopanib for germ tumor cells: A case report

Germ cell tumors with somatic-type malignancy (GCTSTM) are rare, and patients with GCTSTM have extremely poor prognoses with a median survival of nine months. Somatic-type malignancy, which are mainly sarcomas, usually exhibit chemoresistance. The recommended therapy for GCTSTM is radical resection; however, Pazopanib, which is a multityrosine kinase inhibitor, has indicated therapeutic effects for some soft tissue sarcoma components. The current study reports the case of a 21-year-old Asian man who presented with GCTSTM after combined chemotherapy for a primary mediastinal germ cell tumor with multiple lung metastases. Despite the metastases, his disease was stable after continuous administration of Pazopanib for two years and then stopping the medication for four years. To the best of our knowledge, the current report is the first report of a durable response by Pazopanib for GCTSTM, which is a rare outcome.

Immunophenotypic Characterization of Germ Cell Tumor-Derived Primitive Neuroectodermal Tumors: Evidence for Frequent Neuronal and/or Glial Differentiation

CONTEXT.—

Primitive neuroectodermal tumors (PNETs) may arise as a somatic-type malignancy in germ cell tumors. In this setting, most PNETs resemble those of the central nervous system and lack chromosome 22 translocations. However, description of the morphologic and differentiation spectrum of PNETs arising from germ cell tumors is lacking.

OBJECTIVE.—

To investigate the morphologic and immunohistochemical features of these tumors, concentrating on neuronal and glial features.

DESIGN.—

We selected cases based on a morphologically identifiable glial and/or differentiated neuronal component in association with the undifferentiated PNET. Immunohistochemistry for glial fibrillary acidic protein, S100 protein, synaptophysin, chromogranin A, and SOX11 was performed on tumors with available material, with the scoring of both staining intensity (0-3) and extent (0-3). Thirteen qualifying PNETs of testicular origin with available immunohistochemical stains or stainable material were identified. The complete stain panel was performed in 10 tumors.

RESULTS.—

SOX11 demonstrated positive staining in the undifferentiated PNET component of all tumors (10 of 10) and was rarely positive in the differentiated (ie, neuronal/glial) component (1 of 10; focal and weak); synaptophysin was slightly less sensitive in the undifferentiated component (12 of 13; often focal and weak) and also showed positivity in the neuronal/glial component (5 of 13). Glial fibrillary acidic protein and S100 were more frequently positive in the differentiated areas (83% and 77%, respectively) compared with undifferentiated areas (25% and 17%, respectively).

CONCLUSIONS.—

SOX11 is a sensitive immunohistochemical marker for testicular PNET, particularly those lacking differentiation. Testicular PNETs often demonstrate glial and/or neuronal differentiation. Differentiation is marked by the acquisition of S100 and glial fibrillary acidic protein expression and SOX11 loss.

Primary pure angiosarcoma of the testis: a vanishingly rare malignancy. Case report and literature review

Background

Primary pure angiosarcoma of the testis is an exceptionally rare testicular malignancy, which is poorly understood. We present the fifth and youngest case in the current medical literature. Additionally, all cases of angiosarcoma of the testicle, both occurring with associated germ cell tumour and without, were compared in an extended tabular format.

Case presentation

A 56-year old man presented with unilateral scrotal pain, swelling and erythema. Ultrasonography revealed two testicular lesions with a high suspicion of malignancy but serum tumour markers were negative. A radical orchidectomy was performed with clear surgical margins. Diagnosis of primary pure angiosarcoma of the testis was confirmed on subsequent histopathology.

Conclusions

Primary pure angiosarcoma is a rare testicular neoplasm. We present the fifth case in the literature. Clinical and radiological features are non-specific. The diagnosis is purely histological, with the pathologist choosing immunohistochemistry based on abnormal morphology. Local invasiveness is variable but metastatic sites are typical for extra-gonadal angiosarcomas. Primary pure testicular angiosarcoma diagnosis confers a relatively better prognosis compared to angiosarcoma arising in the context of a testicular germ cell tumour. While extra-gonadal angiosarcomas are associated with high rates of local recurrence following resection, in all cases of testicular angiosarcoma there were no local recurrences following radical orchidectomy. Surgical resection remains the most effective treatment for both subtypes of testicular angiosarcoma.

Mediastinal Germ Cell Tumors: Updates in Diagnosis and Management

Primary mediastinal nonseminomatous germ cell tumors represent a rare but important malignancy that occurs in otherwise young and healthy patients. Treatment is challenging and involves cisplatin-based chemotherapy followed by surgery to remove residual disease. Avoiding bleomycin-containing chemotherapy in the treatment of primary mediastinal nonseminomatous germ cell tumors is important. Prechemotherapy and postchemotherapy pathology as well as postoperative serum tumor markers are independent predictors of long-term survival.

Mediastinal sarcomas: experience using fine needle aspiration cytopathology

Fine needle aspiration (FNA) cytology is a sparsely used diagnostic method in the evaluation of mediastinal sarcomas in most medical centers worldwide with most literature citations regarding this category of malignancies consisting of small series and individual case reports. Most of these published studies highlight vascular sarcomas such as epithelioid hemangioendothelioma, and angiosarcoma, various subtypes of liposarcoma including well-differentiated liposarcoma, myxoid liposarcoma, and pleomorphic liposarcoma, malignant peripheral nerve sheath tumor, and sarcomas of uncertain differentiation, primary synovial sarcoma and the Ewing sarcoma family of tumors. This paucity of cytopathology reports regarding mediastinal sarcomas is in marked contrast to the almost daily application of endobronchial ultrasound (EBUS)-guided FNA biopsy for sampling mediastinal lymph nodes and mediastinal masses for primary and metastatic carcinomas which, of course, are considerably more common that any type of sarcoma in this location. EBUS, endoscopic ultrasound-guided (EUS) needle biopsy, and percutaneous image-guided biopsy using either core needle, fine-needle, or both can serve a potentially useful role for diagnostic sampling of mediastinal sarcomas, be they primary or metastatic. This review catalogues much of the published data regarding FNA cytopathology and its application to mediastinal sarcomas. An attempt is made to primarily highlight case series rather than individual case reports; however, due to the paucity of these, case reports are cited and discussed where appropriate.

Testicular Mixed Germ Cell Tumor Combined with Malignant Transformation to Chondrosarcoma: A Very Rare and Aggressive Disease

BACKGROUND Testicular mixed germ cell tumors (GCTs) represent a spectrum of malignancies that differ in terms of histopathology, clinical complications, and overall outcome. A variety of aggressive combinations containing different histological types have been described among such testicular tumors. However, a histopathology characterized by a combination of teratoma and choriocarcinoma, as seen in this case, in which the teratomatous component shows a secondary transformation to chondrosarcoma, is considered very rare. CASE REPORT The patient presented with progressive hemoptysis and dyspnea secondary to bilateral pulmonary cannon-ball lesions indicative of a metastatic process. His workup was remarkable for primary testicular cancer complicated by liver metastasis and very high levels of B-HCG at more than 175 000 mlU/ml. He deteriorated quickly with no improvement following the first cycle of Etoposide/Cisplatin (EP) chemotherapy regimen and died 15 days after starting cancer treatment. Such non-seminomatous GCTs with extrapulmonary visceral metastasis associated with very high tumor markers are deemed poor risk based on the International Germ Cell Cancer Collaborative Group (IGCCCG) criteria, with a reported 5-year overall survival rate reaching up to 73%. CONCLUSIONS This case is considered unique in terms of rapid clinical deterioration and lack of improvement following the standard EP chemotherapy regimen. This unusual dramatic presentation should draw attention to the possible association between the aggressiveness of the disease and its very rare histopathology.

Outcomes following surgery for primary mediastinal nonseminomatous germ cell tumors in the cisplatin era

OBJECTIVE

Treatment of primary mediastinal nonseminomatous germ cell tumors involves cisplatin-based chemotherapy followed by surgery to remove residual disease. We undertook a study to determine short and long-term outcomes.

METHODS

A retrospective analysis of patients with primary mediastinal nonseminomatous germ cell tumors who underwent surgery at our institution from 1982 to 2017 was performed.

RESULTS

A total of 255 patients (mean age, 29.2 years) were identified. Acute respiratory distress syndrome occurred postoperatively in 27 patients (10.9%), which was responsible for all 11 (4.3%) postoperative deaths. Of patients who developed acute respiratory distress syndrome, more patients received bleomycin-containing chemotherapy (25 out of 169; 14.8%) than non-bleomycin regimens (2 out of 77; 2.6%) (P = .004). With respect to variables independently predictive of long-term survival, evidence of choriocarcinoma before chemotherapy (n = 12) was determined to be an adverse factor (P = .006). In contrast, biopsy-proven elements of seminoma (n = 34) were predictive of improved survival (P = .04). The worst pathology identified in the residual mediastinal mass after chemotherapy was necrosis in 61 patients (25.0%), teratoma in 84 patients (34.4%), and malignant (persistent germ cell or non-germ cell cancer) in 97 patients (39.8%), which influenced overall survival (P < .001). Additionally, teratoma with stromal atypia (n = 18) demonstrated decreased survival compared with teratoma without atypia (n = 66; P = .031). Patients with malignancy involving >50% of the residual mass (n = 47) had a 2.3-fold increased risk of death compared with ≤50% malignancy (n = 45; P = .008). Finally, elevated postoperative serum tumor markers (n = 40) was significantly predictive of adverse survival (P < .001).

CONCLUSIONS

In the treatment of primary mediastinal nonseminomatous germ cell tumors, avoiding bleomycin-containing chemotherapy is important. Pre- and postchemotherapy pathology and postoperative serum tumor markers are independent predictors of long-term survival.

Therapeutic strategies for uncommon testis cancer histologies: teratoma with malignant transformation and malignant testicular sex cord stromal tumors

Testicular cancer is the most common solid malignancy in male adolescents and young adults, with germ cell derived seminomas and non-seminomas being by far the most common histologies. Teratoma with somatic-type malignancy is a rare chemo-resistant phenotype of testis cancer associated with poor prognosis in patients with advanced stage disease. Malignant gonadal-stromal tumors comprise 5% of testicular neoplasms and approximately 10% are malignant and considered chemo-radiation resistant. Prognostic factors and treatment strategies for these uncommon histologies are lacking.

Presacral malignant teratoid neoplasm in association with pathogenic DICER1 variation

We report two malignant sacrococcygeal tumors in infants that were associated with pathogenic DICER1 variation. These tumors were composed of primitive neuroepithelium, embryonal rhabdomyosarcoma, and cartilage and initially diagnosed as immature teratomas. One child developed intracranial metastasis and died. The second child underwent surgery and chemotherapy and achieved complete remission. This child subsequently developed five additional DICER1-associated neoplasms by age nine. Genetic analysis revealed that both tumors harbored biallelic pathogenic DICER1 variation. We believe these cases represent another novel subtype of DICER1-associated tumor. This new entity, which we propose to call DICER1-associated presacral malignant teratoid neoplasm, may be difficult initially to distinguish from immature teratoma, but recognizing it as an entity can prompt appropriate classification as an aggressive malignancy and facilitate appropriate genetic counseling, DICER1 germline variant testing, screening, and education.

Rhabdomyosarcoma arising from retroperitoneal teratoma in an infantile neurofibromatosis type 1 patient

We herein report the case of a 2-year-old girl with neurofibromatosis type 1 (NF1), who presented with a 12-cm mass in the right retroperitoneum and underwent tumor resection. Histologically, the tumor was composed of two distinct components: one was teratoma, showing mature morphology; and the other was embryonal rhabdomyosarcoma. An interphase fluorescence in situ hybridization (FISH) analysis of the rhabdomyosarcoma component revealed the absence of isochromosome 12p. Although it is well known that rhabdomyosarcoma occurs in infantile NF1, and that rhabdomyosarcoma can arise from teratoma as a somatic-type malignancy, to the best of our knowledge, this is the first case of an infantile NF1 patient, who developed rhabdomyosarcoma within a retroperitoneal teratoma. The absence of chromosome 12p alteration suggests a possibility that the rhabdomyosarcoma occurred due to the NF1 background, not as a somatic-type malignancy of germ cell tumor.

Postchemotherapy sarcoma as a somatic-type malignancy derived from the gonadal yolk sac tumor in a patient with 46, XY pure gonadal dysgenesis

46, XY pure gonadal dysgenesis (PGD) is characterized as a female phenotype with strip-like gonads, which has a high tendency to develop into gonadal tumors. Somatic-type malignancies of germ cell tumors (SMs of GCTs) refer to the presence of malignant non-germ cell histologies admixed with GCTs, which are usually chemoresistant and indicate poor prognosis. This case report aimed to analyze the special histological type of GCTs and the importance of salvage surgery in the treatment of refractory GCTs. We report a unique case of gonadal yolk sac tumor (YST) transformed into SMs in a patient with 46, XY PGD. This 18-year-old woman underwent laparoscopic pelvic tumor resection, considered her first surgery, 2 years ago, and pathology revealed YST with initial alpha-fetoprotein (AFP) level measuring >3,000 ng/mL. She underwent seven cycles of chemotherapy, and the AFP level decreased to within a normal range after the second cycle. However, a computed tomography scan after the seventh cycle revealed abdominal and pelvic metastases, and vaginal bleeding was continuously observed. Laparoscopic exploration and laparotomy with tumor subtotal resection were performed. A pathology report showed SMs (sarcoma) derived from YST. Whole exome sequencing demonstrated that the main somatic mutation was a non-synonymous mutation of KRAS (c.182A>G), and this result did not show any indications for targeted drugs. She received three cycles of PEI (cisplatin, etoposide, and ifosfamide) chemotherapy but showed no response. She refused to undergo further treatment and has been alive with the disease for 7 months. This suggests that SMs may be one of the reasons for chemoresistance of refractory GCTs, and salvage surgery may be one of the most effective treatments for this patient. Targeted therapy may be a new choice for chemoresistant GCTs, but drug selection must be based on gene sequencing, and its efficacy still needs to be verified by further study.

Development of angiosarcoma in a mediastinal non-seminomatous germ cell tumor that exhibited growing teratoma syndrome during chemotherapy

Herein, we report a case of an angiosarcoma in a mediastinal non-seminomatous germ cell tumor that exhibited growing teratoma syndrome during chemotherapy. A 26-year-old man presented with a giant anterior mediastinal mass, which was diagnosed as a non-seminomatous germ cell tumor. The patient was administered three cycles of chemotherapy (bleomycin, etoposide, and cisplatin), but the mass grew despite normalization of tumor markers. Massive bleeding during thoracic surgery resulted in incomplete resection, and the mass was clinically and pathologically diagnosed as growing teratoma syndrome (only mature teratoma). The residual mass continued to grow, and complete resection was subsequently achieved after a detailed analysis of its vascular anatomy using angiography. The final pathological findings revealed angiosarcoma, which indicated a rare somatic type of mediastinal non-seminomatous germ cell tumor.

Vasoformative Lesions in Mediastinal Mixed Germ Cell Tumors: an Interesting Account of Two Cases Spanning the Benign to Malignant Spectrum

Extragonadal germ cell tumors are most commonly encountered in the anterior mediastinum. The presence of sarcomatous malignancies in these tumors is a rare phenomenon that adversely impacts patient prognosis because of poor response to conventional cisplatin-based chemotherapy. Even more unusual is the presence of florid benign somatic proliferations that overshadow the germ cell component, often resulting in misdiagnosis and inappropriate management. Two young male patients aged 17 and 28 years respectively presented with mass in the anterior mediastinum. Histopathology of both cases revealed mixed germ cell tumor admixed with prominent vascular component. Interestingly, one case showed malignant vasoformative neoplasm (angiosarcoma) while in the other the vascular proliferation was of benign nature (venous hemangioma).

Gonadal dysgenesis is associated with worse outcomes in patients with ovarian nondysgerminomatous tumors: A report of the Children's Oncology Group AGCT 0132 study

PURPOSE

In this report, we characterize the timing and behavior of malignant ovarian germ cell tumors (GCTs) in pediatric patients with dysgenetic gonads compared to those with normal gonadal development.

PATIENTS AND METHODS

Patients from the Children's Oncology Group AGCT0132 with malignant ovarian GCTs were included. Within this population, we sought to identify patients with gonadoblastoma, streak ovaries, or other evidence of gonadal dysgenesis (GD). Patients with malignant GCTs containing one or more of the following histologies-yolk sac tumor, embryonal carcinoma, or choriocarcinoma-were included. Patients were compared with respect to event-free survival (EFS) and overall survival (OS).

RESULTS

Nine patients with GD, including seven with gonadoblastoma (mean age, 9.3 years), were compared to 100 non-GD patients (mean age, 12.1 years). The estimated 3-year EFS for patients with GD was 66.7% (95% CI 28.2-87.8%) and for non-GD patients was 88.8% (95% CI 80.2-93.8%). The estimated 3-year OS for patients with GD was 87.5% (95% CI 38.7-98.1%) and for non-GD patients was 97.6% (95% CI of 90.6-99.4%).

CONCLUSION

Patients presenting with nongerminomatous malignant ovarian GCTs in the context of GD have a higher rate of events and death than counterparts with normal gonads. These findings emphasize the importance of noting a contralateral streak ovary or gonadoblastoma at histology for any ovarian GCT and support the recommendation for early bilateral gonadectomy in patients known to have GD with Y chromosome material. In contrast to those with pure dysgerminoma, these patients may represent a high-risk group that requires a more aggressive chemotherapy regimen.

Primary high grade testicular leiomyosarcoma: A rare malignancy in a young male

A 27-year-old male presented with a gradually increasing left scrotal mass. There was no significant past medical history. Ultrasonography of the left scrotum showed a hypoechoic, intratesticular mass with solid and cystic components. Laboratory investigations revealed normal serum levels of alpha-fetoprotein, beta human chorionic gonadotropin and lactate dehydrogenase. He underwent left high inguinal orchidectomy due to suspicion of testicular malignancy. After histopathologic examination and immunostaining, a diagnosis of high-grade primary testicular leimyosarcoma was ascertained. Only a few cases of primary intratesticular leiomyosarcoma have been reported in literature with the mean age of presentation of 50 years. In younger individuals, these tumors have been reported in a setting of predisposing factors like anabolic steroid use, testicular germ cell tumors, chronic inflammation of testis and testicular field radiation for treatment of leukemia. We present a case of high grade leiomyosarcoma of testis in a young male without any known predisposing factors.

Hepatic angiosarcomatous transformation of a mediastinal germinal cell tumor: A care case report

RATIONALE

Mediastinal nonseminomatous germ cell tumor (NSGCT) is an uncommon entity. Metastatic hepatic sarcomatous transformation is rare.

PATIENT CONCERNS

We report a 24-year-old man with no previous related medical history presented with chest pain and left arm numbness.

DIAGNOSES

The x-ray showed an anterior mediastinal mass. The chest computed tomography (CT) confirmed the presence of a mildly enhancing mass in the same location, without invasion of any vascular structure. A CT-guided biopsy was performed, revealing a primary mediastinal nonseminomatous germ cell tumor (NSGCT), yolk sac histology, with areas of somatic transformation to malignant nerve sheath tumor. After surgery patient was followed-up with imaging. Two years later a CT scan showed a new hepatic hyper vascular lesion, confirmed by a subsequent magnetic resonance imaging (MRI) and positron emission tomography (PET) scan. A CT-guided biopsy revealed a hepatic metastatic transformation to angiosarcoma of the primitive NSGCT.

INTERVENTIONS

The patient went on to received palliative chemotherapy.

OUTCOMES

The patient is being followed-up regularly at the outpatient department.

LESSONS

Because of the potential of metastatic sarcoma arising from germ cell tumors, these patients should undergo periodical follow-up, with periodical scans. PET\CT scan might have a role in the follow-up of these patients.

Radiological-pathological correlation of malignant teratoma with liposarcomatous transformation: Proven by repeated transthoracic needle biopsy

A mediastinal germ cell tumor with a sarcomatous component is extremely rare and is accompanied by a poor prognosis. Clinical and radiologic diagnosis is very difficult. Herein, we report a rare case of anterior mediastinal malignant teratoma containing a growing liposarcomatous component and detail the diagnostic process. The case was diagnosed by repeated transthoracic needle biopsy and correlated with changes in follow‐up chest computed tomography and serum tumor markers. We also provide a review of the literature.

Two Tumors in 1: What Should be the Therapeutic Target? Pediatric Germ Cell Tumor With Somatic Malignant Transformation

BACKGROUND

Germ cell tumors with somatic malignant transformation (GCT with SMT) are rare in children and poorly described. Data are missing to determine if therapies should target the GCT, the SMT compound, or both simultaneously.

PATIENTS AND METHODS

A retrospective national study was conducted in the Société Française des cancers de l'Enfant (SFCE) Centers. Medical records from patients aged 0 to 18 years diagnosed with GCT with SMT between 2000 and 2015 were analyzed. Any stages and primary sites were considered as well as synchronous and metachronous cases.

RESULTS

Fifteen patients were identified. Thirteen patients had synchronous GCT with SMT. In the latter cases, primaries were ovary (5), mediastinum (3), pineal gland (3), sacrococcyx (1), and parametrium (1). SMT histologies were central primitive neuroectodermal tumor (5), embryonal rhabdomyosarcomas (3) or thyroid papillary adenocarcinoma, leukemia, poorly differentiated carcinoma, mixed sarcomas, and miscellaneous histology (1 case each). Chemotherapy was targeted against the GCT (3), the SMT (6), or both components (3). The last patient received surgery exclusively. Partial or complete response to chemotherapy was observed in 5/10 assessable cases: 2/3 patients treated with GCT-dedicated chemotherapy, 3/6 patients treated with SMT-dedicated therapy, and 0/1 treated with combined therapy. In addition, 2 patients with mediastinal GCT primary had metachronous SMT, with acute myeloid leukemia and thyroid papillary adenocarcinoma, 8 months and 8 years, respectively, after the diagnoses of GCT. Two patients (1 synchronous and 1 metachronous) were cured with surgery exclusively. At the end of follow-up, 6 patients died of their disease including all 4 with postsurgical macroscopic residue.

CONCLUSIONS

GCT with SMT constitutes a very rare entity in children and adolescents. Surgical removal of the tumor is the cornerstone of the treatment and might be sufficient in selected cases. In the remaining cases, the best management is still unknown and should take into account both components and their respective chemosensitivity. Long-term surveillance is advised for patient with unresected teratoma as late transformation can occur.

Pure Testicular Seminoma Relapsing Late with Somatic Type Malignancy

Background. Somatic type malignancy (STM) occurs in 2% of all germ cell tumours (GCTs). The prognosis is unfavourable and the origin is poorly understood. Pathogenetic hypotheses involve direct transformation of teratoma, origin from totipotent cancer cells, or derivation from yolk sac tumour elements. Case Presentation. A 31-year-old patient was cured from testicular seminoma clinical stage IIc by orchiectomy and cisplatin-based chemotherapy. Nine years later, he experienced a late relapse with a mass sized 5 × 6 cm located at the former metastatic site. As no remission occurred after chemotherapy with three cycles of cisplatin, ifosfamide and etoposide, the mass was surgically resected. Histologically, the specimen consisted of neurofibroma with areas of malignant peripheral nerve sheath tumour and spots with mature bone formation. FISH analysis disclosed isochromosome 12p in the majority of evaluated cells suggesting somatic type malignancy (STM) of GCT. The patient is well 1 year after surgery. Conclusion. The pathogenesis of this STM remains enigmatic. The origin from GCT was evidenced by documentation of isochromosome 12p. Unrecognized teratomatous elements in the primary and totipotent cancer cells surviving the first chemotherapy could be hypothesized to represent the origin. STM developing from seminoma cells would be another novel hypothesis.