Teratoma with malignant transformation: report of three cases and review of the literature

Teratoma with malignant transformation is an uncommon, very aggressive germ cell tumor that has undergone transformation of a somatic teratomatous component to a histologic type identical to a somatic malignancy. We review the clinical presentation, imaging appearances, and prognosis of this entity and highlight its aggressive behavior by reporting on three patients with metastatic testicular nonseminomatous germ cell tumor with histologically proved malignant transformation.