Massive pericardial effusion due to intrapericardial mixed germ cell tumor in a premature baby

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.

Pericardial effusion as an atypical initial presentation of extra-gonadal nonseminomatous germ cell tumor: a case report and literature review

Extra gonadal germ cell tumors have variable clinical presentations and locations. We report a case of an extra-gonadal germ cell tumor in a 26-year-old male who presented with chest pain. Imaging revealed a large pericardial effusion with underlying mass invading the pericardium. Pericardial effusion is an extremely rare initial site of diagnosis or site of metastasis for malignancy. This case illustrates the importance of a thorough history and physical examination, broad differential diagnosis, and to keep in mind serious complications from rare presentations of disease.