Primary Mixed Germ Cell Tumor Research Articles

Extragonadal Mixed Germ Cell Tumor Presenting as Large Mass in the Pelvic Cavity

Extragonadal germ cell tumors are relatively rare tumor, which usually occurs in the mediastinum or retroperitoneum. In this report, we present a case of primary mixed germ cell tumor (GCT) arising in the pelvic cavity. A 38-year-old male with acute abdominal pain was admitted to our hospital. Computed tomography scan imaging demonstrated a large mass in the pelvic cavity. Histological examination of the specimen revealed germ cell tumor with dual morphology. Immunohistochemical studies detected placental alkaline phosphatase (ALP), OCT3/4, ALP, and pancytokeratin. Taking these results together with the patient's other clinical manifestations, this case was diagnosed with mixed GCT, i.e., seminoma plus yolk sac tumor. Chemotherapy was successful. Mixed germ cell tumor in the pelvic cavity is extremely rare but should be considered as a cause of pelvic mass formation.

Primary mixed germ cell tumor arising in the pancreatic head

Germ cell tumors, comprised of gonadal and extra-gonadal types, are relatively rare tumors arising from primordial germ cells. Extra-gonadal germ cell tumors have been reported to occur at many non-gonadal locations, from the brain to the sacrococcygeal region. However, primary germ cell tumors in the pancreas are extremely rare. Herein, we present the first case of a 12-month-old girl with a primary mixed germ cell tumor, consisting of both endodermal sinus tumor and mature teratoma, in the pancreatic head.

Mixed germ cell tumor with extensive yolk sac tumor elements in the frontal lobe of an adult.

Intracranial nongerminomatous germ cell tumors (NGGCTs) in unusual locations are extremely rare. Here, we report a case of a yolk sac tumor in the frontal lobe in a middle-aged patient. A 42-year-old man was admitted to our hospital for headache and nausea. Magnetic resonance imaging (MRI) showed an enhanced mass lesion with a marked cyst component. The serum alpha-fetoprotein (αFP) level was extremely high. Histological examination of specimens after subtotal removal revealed a primary mixed germ cell tumor with extensive yolk sac tumor elements, often referred to as an intracranial “yolk sac tumor.” The preoperative diagnosis of NGGCTs in unusual age and locations is extremely difficult. Clinicians should consider the possibility of NGGCTs, including yolk sac tumors, when intracranial tumors with unusual MRI findings are encountered.

Primary mixed germ cell tumor of the liver with sarcomatous components

Germ cell tumor (GCT) of the liver is extremely rare. Here, we describe a case of hepatic mixed GCT with significant sarcomatous components and elevated serum alpha-fetoprotein (AFP) in a 34-year-old man. Histopathologically, the tumor was composed of two GCTs components: yolk sac tumor and immature teratoma. The predominant components of immature teratoma consisted of several types of tissue that represented different germinal layers (endoderm, mesoderm and ectoderm) and showed varying degrees of differentiation with significant sarcomatous components. The yolk sac component showed positivity for AFP and cytokeratin (AE1/AE3). The immature teratoma components showed positivity for varying differentiation markers. Interphase cytogenetic analysis revealed that the yolk sac tumor and immature teratoma were positive for i(12p) and 12p over-representation. In particular, the rhabdomyoblastic components also showed typical i(12p) and 12p overrepresentation. This suggested that sarcomatous components may be associated with dedifferentiation or malignant transformation of certain mesenchymal components within teratoma.