Hepatocellular carcinoma arising in a testicular teratoma: a distinct and unrecognized secondary somatic malignancy

We report an interesting case of testicular germ cell tumor with distinct seminomatous and teratomatous components. A rare development of secondary somatic malignancy in the form of hepatocellular carcinoma was observed. Immunohistochemically, hepatocellular cancer was positive for cytokeratin, hepatocyte paraffin-1 (HepPar-1), α-fetoprotein, glypican-3 (GPC-3), octamer-binding transcription factor 3/4 (Oct3/4), and Ki-67. In addition, adenocarcinoma and rhabdomyoblastic differentiation were also evident. Placental alkaline phosphatase (PLAP), Sal-like 4, and Oct3/4 were positive in seminoma. To the best of our knowledge, we have not found any such report of secondary development of hepatocellular carcinoma in a testicular teratoma. We believe that it is a rare, distinct phenomenon in germ cell tumors and deserves recognition.