A bilateral primary yolk sac tumor of the lung associated with chromosome 3 polysomy: understanding the Oct 3/4 and Sox 2 interaction.

Extragonadal germ cell tumors (EGCTs) in the lung are extremely rare and their pathogenesis is poorly understood. We report a case in a 48-year-old female which was very aggressive and stained positive for primoridial germ cell markers. Interestingly, there was chromosome 3 polysomy noted. To our knowledge this is the first chromosomal aberration noted in a primary germ cell tumor of the lung.