Mediastinal endodermal sinus tumor associated with fatal hemophagocytic syndrome.

The association of endodermal sinus tumor, known also as yolk sac tumor, of the mediastinum with hemophagocytic syndrome is exceedingly rare with only a few cases on record. We report a 24-year-old male who had a large mediastinal germ cell tumor, proven to be an endodermal sinus tumor on biopsy. The patient developed pancytopenia and coagulopathy related to associated hemophagocytic syndrome, with a fatal outcome.