Non-germ cell tumours arising in germ cell tumours (teratoma with malignant transformation) in men: CT and MR findings

Somatic-type Malignancies of Germ Cell Origin: Molecular, Pathologic, and Clinical Features

Somatic-type malignancies (STMs) arising in germ cell tumors are relatively rare, affecting 3% to 8% of patients. These neoplasms show aggressive clinical behavior and are frequently resistant to systemic therapy. In the current review, we provide a comprehensive clinicopathologic overview of these tumors, emphasizing new molecular findings that have improved our understanding of their pathogenesis. In all areas, we highlight special considerations related to the different histologic subtypes. We conclude with a brief mention of areas of uncertainty and areas that require further study.

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.

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.

Squamous cell carcinoma as a somatic-type malignancy in an extragonadal immature teratoma of the sinonasal region

Somatic-type malignancy arising in a teratoma of the sinonasal region is extremely unusual, creating a diagnostic dilemma. There are no definite guidelines for management of such cases. A 15-year-old male with a maxillary mass was misdiagnosed as angiomyolipoma, maxillary carcinoma, mucoepidermoid carcinoma, and teratocarcinosarcoma, followed by the final diagnosis of squamous cell carcinoma arising in an immature teratoma. He received neoadjuvant chemotherapy, followed by surgery and chemo-radiotherapy, and is disease-free at 21 months. This case highlights the difficulty faced when diagnosing neoplasms unusual to the head and neck region, particularly on small biopsies, and good outcome following appropriate multimodality management.

Mediastinal Yolk Sac Tumor Producing Protein Induced by Vitamin K Absence or Antagonist-II

Extragonadal yolk sac tumors (YSTs) are rare. We herein report the case of a 66-year-old man with mediastinal, lung and liver tumors. The largest mass was located in the liver and contained a high concentration of protein induced by vitamin K absence or antagonist-II (PIVKA-II) and alpha-fetoprotein. Therefore, the lesion was difficult to distinguish from hepatocellular carcinoma. Finally, YST was diagnosed based on the results of a liver biopsy. Although chemotherapy was effective, the patient died of respiratory failure. The autopsy revealed primary mediastinal YST. In the current report, we describe this case of PIVKA-II-producing YST and review previous cases of PIVKA-II-producing tumors other than hepatoma.

Teratoma with malignant transformation: report of three cases and review of the literature

Teratoma with malignant transformation is an uncommon, very aggressive germ cell tumor that has undergone transformation of a somatic teratomatous component to a histologic type identical to a somatic malignancy. We review the clinical presentation, imaging appearances, and prognosis of this entity and highlight its aggressive behavior by reporting on three patients with metastatic testicular nonseminomatous germ cell tumor with histologically proved malignant transformation.

[Mediastinal mature teratoma with spontaneous malignant transformation]

INTRODUCTION

Malignant teratomas can be either immature teratomas or they can develop after treatment of other malignant germ cell tumors with chemotherapy or radiotherapy. Spontaneous malignant transformation of mature teratomas is very rare.

OBSERVATION

We report the case of a patient complaining of atypical chest pain. Chest plain radiography showed a right anterior mediastinal mass. Computed tomography revealed a heterogeneous mediastinal mass with fat areas and calcification. There were hilar and mediastinal lymph nodes as well as lung parenchymal nodules. CT-guided and then surgical biopsies confirmed the diagnosis of a mature teratoma, which had degenerated into a digestive adenocarcinoma.

CONCLUSION

Spontaneous malignant transformation of mature mediastinal teratoma is very rare. The diagnosis of malignant transformation is based on radiological examinations, laboratory tests and histological studies.

Teratoma with malignant transformation: a case report with pathological, cytogenetic, and immunohistochemistry analysis

Background. Teratoma with malignant transformation (TMT) is rare and most commonly encountered in adult patient with germ cell tumor (GCT). Method. We report a rare case of testicular teratoma with metastatic TMT/embryonal rhabdomyosarcoma (ERMS). A 44-year-old man underwent right orchiectomy which revealed a malignant teratoma, he subsequently had right pneumonectomy with two pulmonary masses containing a high-grade embryonal rhabdomyosarcoma. The patient developed liver metastasis three months after initial diagnosis. He was treated with a chemotherapy regimen with vincristine, dactinomycin, and cyclophosphamide (VAC) alternating with vincristine and irinotecan (VI) with complete resolution of his liver lesion. The tumors were examined with a battery of cytogenetic, immunohistochemical, and molecular assays. Results. The malignant cells were immunohistochemically positive for desmin, myogenin, and MyoD1. Molecular cytogenetics of embryonal rhabdomyosarcoma tissue revealed the presence of i(12p). The tumor expressed high level of TOPO2A, TOPO1, MRP1, MGMT, BCRP, ERCC1, RRM1, and TS. Conclusion. The activity of topoisomerase inhibitors and the potential usefulness of topoisomerase expression as biomarkers should be further tested in aprospective study.

Adult extragonadal germ cell tumors

OBJECTIVE

The purpose of this article is to describe the key imaging features of primary and metastatic extragonadal germ cell tumors in adults.

CONCLUSION

Extragonadal germ cell tumors primarily affect men during the third and fourth decades of life. Their imaging characteristics are nonspecific, and extragonadal germ cell tumors should always be included in the differential diagnosis of a midline anterior mediastinal or retroperitoneal mass. Levels of human chorionic gonadotropin or α-fetoprotein or both may be elevated, depending on the histologic subtype.

[Imaging of mediastinal tumors]

Imaging of mediastinal tumors is an important part of the diagnostic workup in patients presenting symptoms suggestive of compression of one or more of the mediastinal components. In other cases, lesions growing within the mediastinum remain asymptomatic and are diagnosed when chest X-ray or CT are routinely performed for other indications. CT remains the most available and reliable tool among the different imaging methods. Due to its permanent technical improvements, it can be used as the one-step answer to all the requirements of the pretherapeutic evaluation of a mediastinal mass. Chest plain film is still needed as the first line examination in order to carefully select the acquisition protocol for CT. MR did not demonstrate any superiority to CT except for the preoperative workup of lesions arising in the posterior part of the mediastinum. MR remains an interesting tool for tissue characterisation. Topography of mediastinal lesions (based upon the definition of mediastinal compartments) is one of the guides through the diagnostic pathway in imaging these tumors. The other one is their main tissue component, so that cystic, fatty and soft tissue masses can be differentiated.