Mediastinal germ-cell tumors in adults are unusual, representing 2-5% of germ-cell tumors and only 1-10% of all mediastinal tumors. We report a case of a large mediastinal mixed germ-cell tumor composed of seminoma, mature teratoma, ganglioneuroblastoma and an invasive squamous cell carcinoma. Such an association is extremely rare in adult patients.
A 42-year-old Mexican man with a medical history of type 2 diabetes, hypertension and occasional tobacco use presented with chest pain and dyspnea. A chest CT scan showed a large anterior mediastinal tumor (12.0x9.5x7.0 cm) This finding was confirmed with a MRI of chest. Theta fraction of human chorionic gonadotropin (β-HCG) and alpha-fetoprotein (AFP) were within normal values. The patient was referred to our hospital for surgical management. Testicular ultrasound revealed no abnormalities, and staging studies revealed no evidence of metastases. The tumor was approached through a median sternotomy and resected. Histopathological reports of our hospital and M.D. Anderson Cancer Center reported four different histologic types: seminoma, teratoma, and an invasive squamous cell carcinoma and a ganglioneuroblastoma arising from the teratoma. The patient received a double chemotherapeutic regime consisting of four courses of platinum-based therapy and etoposide (plus radiotherapy), followed by four courses of Docetaxel. At all times the β-HCG and AFP were within normal values. Nine months after diagnosis the patient has no signs of recurrence or metastasis.DISCUSSION: The sole presence of a primary mediastinal mixed germ-cell tumor is associated with a poor prognosis, with only 30% of patients achieving cure. But the presence of multiple histologic types represented a therapeutic challenge. Prognosis is especially poor for mediastinal teratomas with malignant transformation and for those with neural differentiation.CONCLUSSION: Mediastinal germ-cell tumors in adults are unusual, and often associated with poor prognosis. The management of mixed germ-cell tumors of the mediastinum represents a challenge for clinicians. This case has presented a unique combination of four histologic types that we believe to be the first described in literature.
E. Fernandez-Rangel, None.