Gonadal mixed germ cell tumor combined with a large hemangiomatous lesion in a patient with Turner's syndrome and 45,X/46,X, +mar karyotype.

In this report, we describe bilateral gonadal tumors with characteristic histopathological findings in a patient with Turner's syndrome who had 45,X/46,X, +mar mosaicism. The left gonad contained a gonadoblastoma and a remnant of streak gonad. The right gonad was entirely replaced by a 15x11x7-cm solid and cystic tumor, which was revealed to be a combination of a mixed germ cell tumor and a cavernous hemangiomatous lesion. The latter occupied approximately half of the entire tumor volume, and there was an incomplete boundary between it and the mixed germ cell tumor lesion. To our knowledge, this is the first reported case of Turner's syndrome with a combination of a mixed germ cell tumor and a hemangiomatous lesion in the gonad.