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

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.

Primitive Neuroectodermal Tumor (PNET) as Somatic-Type Malignancy Arising from an Extragonadal Germ-Cell Tumor: Clinical, Pathological and Molecular Features of a Case

We report a rare case of a 34-year-old man with a right axillary mass. Ten years previously, he had been diagnosed with a right scapular nonseminomatous germ-cell tumor consisting of teratoma, completely resected without any further treatment. Presently he was found to have a metastatic malignant small round cell tumor consistent with a secondary somatic malignancy arising in the background of nonseminomatous germ-cell tumor, teratoma, yolk sac tumor, and primitive neuroectodermal tumor with distinct chromosome 22 translocation. Although the patient initially responded well to chemotherapy with etoposide, cisplatin, ifosfamide and mesna, he relapsed shortly after.

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.

Surgical resection of a huge ruptured mature mediastinal teratoma

Usually slow-growing and benign, mature mediastinal teratomas are rare clinical entities. They may be complicated by rupture into the pleural or pericardial spaces, lungs, or bronchi. Complete surgical resection is the treatment of choice and is usually curative. We report the unusual case of a 24-year-old woman presenting 15 weeks postpartum with a huge ruptured mature mediastinal teratoma superinfected with Mycobacterium avium Catastrophic bleeding from the superior vena cava was encountered on mobilization of adhesions attached to it, requiring extracorporeal membrane oxygenator support for control. Histopathological examination confirmed a 12.0 × 7.8 × 4.5-cm differentiated teratoma without malignant transformation.

Surgery for huge mediastinal tumors

BACKGROUND

Mediastinal tumors can reach a huge size and give rise to serious surgical and oncological problems.

METHODS

A review of 18 patients with huge mediastinal tumors was performed. Ages ranged from 16 to 61 years, and 10 were male. In 4 cases, exploratory thoracotomies had been undertaken in other hospitals; in one patient, the tumor recurred after incomplete resection. We performed a median sternotomy in 17 patients and a lateral thoracotomy in one. Radiotherapy and platinum-based chemotherapy was administered in cases found to be malignant.

RESULTS

In 15 patients, the tumor was removed completely. In one patient, the operation was palliative because of vena caval and atrial invasion, and another had exploration only; biopsies revealed malignant transformation in these 2 patients. The blood loss was 425-2530 mL (average 690 mL); bleeding was fatal in one patient. Tissue diagnosis showed mature teratomas in 10 patients. Foci of malignant transformation were found in 5 cases. Chemodectoma was found in one patient, and thymoma in two. Patients with mature teratomas are free of disease. Two patients with malignant teratomas died from tumor recurrence despite irradiation and chemotherapy.

CONCLUSIONS

Clinical and oncological problems lie in the fact that malignant transformation of the tumor is diagnosed only after surgery. Extensive blood loss is a crucial surgical problem. Median sternotomy is the optimal operative approach. Surgical treatment of mature mediastinal tumors results in good outcomes unless malignancy is detected.

Naturally occurring mediastinal teratoma with malignant transformation in an adult male

We report a rare case of rhabdomyosarcoma spontaneously arising in an anterior mediastinal teratoma in a 47-year-old male. The patient was found to have an anterior mediastinal mass on a chest X-ray, which was taken two months before his presentation to Asan Medical Center. A subsequent computed tomography scan revealed an 8.9×7.1×8.0 cm heterogeneous mass in the anterior mediastinum. He underwent an excision via median sternotomy. The histopathologic study identified a mature teratoma with embryonal rhabdomyosarcoma.

[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.

Adenocarcinoma with sarcomatous dedifferentiation arising from mature cystic teratoma of the anterior mediastinum

Mediastinal teratoma with malignant transformation (TMT) is a very rare condition. A 44-year-old man presented with a large cystic mass of the anterior mediastinum. The tumor was surgically removed. The cystic mass was well demarcated, with an irregularly thickened wall. Histologically, the cystic wall was mainly lined by non-ciliated columnar epithelium and focally by squamous epithelium. A nodular part of the cystic wall revealed well-differentiated adenocarcinoma composed of tubulopapillary structures. Deep in the nodular tissue, neoplastic glands merged into undifferentiated sarcomatous cells. Immunohistochemically, CK7, CK19, and smad-4 were strongly and diffusely positive in adenocarcinoma. CD10 was focally positive on the luminal surface of the glands, and MUC5AC was also focally positive. TTF-1, cdx-2, and CK20 were negative in the adenocarinoma. Sarcomatous area showed diffuse strong positivity for vimentin, but was negative for the aforementioned epithelial markers. About 10 months postoperatively, a left pleural effusion had developed with multiple pleural nodules on computed tomography scan of the chest. The cytologic diagnosis from pleural fluid was metastatic adenocarcinoma. To our knowledge, in the English literature, this is the first case of adenocarcinoma with sarcomatous transformation that has developed in a mature cystic teratoma of the mediastinum and shows pleural metastasis.

Mature cystic teratoma with malignant transformation to adenocarcinoma

An anterior mediastinal tumor had been found in a 65-year-old woman 10 years previously, and she had been followed-up under the diagnosis of a mature cystic teratoma. Changes in the structure of the inside of the mediastinal cystic tumor were observed on a chest computed tomography image, and she was referred to our hospital for surgical intervention. The tumor was removed and was determined to be a mature teratoma. An adenocarcinoma was also observed in part of this cystic lesion. From these findings, the lesion was diagnosed as a malignant change in a mediastinal mature teratoma. Because few if any changes tend to be observed in the cystic wall of such cases, an aggressive resection of such mature cystic teratomas is therefore recommended.

Teratoma with naturally occurring malignant transformation in a child

We present a 12-year-old girl with a teratoma with malignant transformation (TMT) of the mediastinum. Computed tomography showed a cystic mass (5.0 cm × 4.0 cm) with a thick solid portion, in the anterior mediastinum. Six months later, the solid portion of the mass had enlarged, and surgical resection was performed. The resected tumor was 7.0 × 5.0 × 4.0 cm in size. The cystic portion was a mature teratoma, and the solid portion predominantly comprised a viable embryonal rhabdomyosarcoma. There were no immature teratomatous elements or other germ-cell components. The histopathologic diagnosis was a mature teratoma with embryonal rhabdomyosarcoma, a so-called TMT. The tumor recurred, despite adjuvant chemotherapy. The patient died of progressive disease 16 months postoperatively. To the best of our knowledge, no naturally occurring TMT of the mediastinum has previously been reported in a child. Surgical resection at an early stage is necessary.

Cystic malignant teratoma with early recurrence after intraoperative spillage

Teratoma with malignant transformation, defined as germ cell tumors with a malignant component of nongerm cell tumors, such as sarcomas and carcinomas, is rarely seen in the mediastinum. A rare case of the mediastinal mature cystic teratoma with focal gastrointestinal adenocarcinoma is described in this report. The patient underwent a video-assisted thoracoscopic surgery for tumor resection. Intraoperatively, the cystic tumor was ruptured due to dense adhesion. The rapid tumor dissemination was postoperatively noted. Careful and complete resection with the cyst wall of the mediastinal mature cystic teratoma intact is necessary to avoid a risk of relapse from a potentially malignant component.

Adenocarcinoma arising in anterior mediastinal mature cystic teratoma: report of a case

Mediastinal mature teratoma with malignant components is a very rare condition. A 57-year-old man presented with a large (14 x 10 cm) encapsulated and lobulated cystic mass involving the anterior mediastinum. The most consistent diagnosis on the basis of radiological findings was mature cystic teratoma, and a surgical resection was thus indicated. The operation was performed through a median sternotomy, and the tumor was extirpated with a combined resection of the pericardium and left mediastinal pleura. Although the pathological diagnosis was mature cystic teratoma, this patient showed a recurrence of malignant effusion 7 months following the operation. The earlier resected specimen was pathologically re-reviewed according to the blocked entire mass, and small foci of adenocarcinoma were thus found within the tumor.

Malignant ganglioneuroma arising from mediastinal mixed germ cell tumor

Mixed germ cell tumors with non-germ cell malignant components rarely occur in the anterior mediastinum. We report a case of a 34-year-old man who presented with an anterior mediastinum mass. Mixed germ cell tumor was initially diagnosed based on the pathologic findings of germinoma on thoracoscopic biopsy and clinical findings of elevated serum alpha-fetoprotein and beta-human chorionic gonadotropin. The patient received preoperative chemotherapy and subsequent complete resection of the residual tumor. Pathologic examination of the excised specimen showed predominantly malignant ganglioneuroma and small residual foci of teratoma. To our knowledge, this is the first reported case of a malignant ganglioneuroma arising from mediastinal mixed germ cell tumor.

Primary mediastinal malignant germ cell neoplasms: imaging features

Mature teratomas are the most frequent primary mediastinal GCN. These are spherical multilocular cystic masses with thin, soft tissue septa and frequent internal fat attenuation. Primary mediastinal malignant GCNs are rare and should be included in the differential diagnosis of anterior mediastinal masses in young adult males. Seminomas are typically homogeneous masses indistinguishable from lymphomas. Radiologically nonseminomatous malignant germ cell neoplasms are large, locally invasive heterogeneous masses with central low-attenuation and frond-like peripheral soft tissue. Gonadal primary malignancy and intervening abdominal lymph node involvement should be excluded. Tumor markers play a crucial role in the initial evaluation of anterior mediastinal masses in these patients and in evaluating response to therapy and possible recurrence. Follow-up imaging is helpful in detection and characterization of residual neoplasm.