Mediastinal germ cell tumors with an angiosarcomatous component: a report of 12 cases.

The development of an angiosarcomatous component in germ cell tumors is rare. Here we studied 12 cases of mediastinal germ cell tumors with an angiosarcomatous component. All patients were men with a mean age of 34 years (range, 24-49 years). No patient had a documented testicular germ cell tumor. The mean size of mediastinal tumors was 12.9 cm (range, 5.5-16.0 cm). Grossly, the tumors were cystic with variegated hemorrhagic, mucinous, and fleshy solid areas. Microscopically, all tumors were composed of germ cell tumor. The most common germ cell tumor component was teratoma (n = 10); and other germ cell tumor components included seminoma (n = 3), yolk sac tumor (n = 3), embryonal carcinoma (n = 2), and choriocarcinoma (n = 1). The angiosarcomatous component was present in primary mediastinal tumors (n = 6), metastasis (n = 3), or both primary mediastinal tumor and metastasis (n = 3). The angiosarcomatous component accounted for an average of 30% (range, 5%-95%) of the primary mediastinal tumor. In addition, other non-germ cell components, including rhabdomyosarcoma (n = 3), leiomyosarcoma (n = 1), and poorly differentiated carcinoma (n = 1), were also present in the tumors. Of the 10 patients with follow-up available, all patients developed metastasis (n = 8) or local recurrence (n = 2); 7 died of disease at a mean of 33 months (range, 21-75 months), and 3 patients were alive at a mean of 75 months (range, 5-120 months). Our findings suggest that the presence of an angiosarcomatous component in mediastinal germ cell tumor, even in a small amount, is associated with a poor clinical outcome.