J Neurol Surg B Skull Base 2013; 74 - A106
DOI: 10.1055/s-0033-1336233

Systematic Analysis of Diagnostic Molecular Markers for Intracranial Germ Cell Tumors

Daniel T. Nagasawa 1(presenter), Michael Sun 1, Andy Trang 1, Andrew Yew 1, Yinn Cher Ooi 1, R. Aaron Robison 1, Gabriel Zada 1, Isaac Yang 1
  • 1Los Angeles, CA, USA

Introduction: Intracranial germ cell tumors (GCTs) are rare neoplasms that share many similarities with their more common ovarian and testicular counterparts. These tumors, comprised of several histological subtypes, often originate in pineal or suprasellar locations and carry a wide range of treatment options and outcomes.

Methods: We conducted a case series and systematic analysis of all documented series of intracranial GCTs throughout the literature. Data were extracted, aggregated, and analyzed for each GCT subtype to characterize various molecular markers and evaluate their diagnostic potential. Markers included serum and cerebrospinal fluid (CSF) levels of alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG), as well as immunohistochemical (IHC) findings for AFP, HCG, placental alkaline phosphatase (PLAP), carcinoembryonic antigen (CEA), human placental lactogen (HPL), cytokeratins, OCT4, and c-kit.

Results: Germinomas displayed elevated levels of serum HCG (25%), CSF HCG (73%), and serum AFP (2%), with IHC positive for HCG (29%), PLAP (93%), CEA (2%), HPL (11%), cytokeratins (22%), OCT4 (100%), and c-kit (100%). Yolk sac tumors were positive for serum AFP (100%), with IHC positive for AFP (100%), PLAP (60%), CEA (50%), and cytokeratins (100%). Embryonal carcinoma was positive for serum AFP (56%), CSF AFP (80%), serum HCG (67%), and CSF HCG (80%), with IHC positive for AFP (67%), HCG (67%), PLAP (25%), CEA (33%), HPL (50%), and OCT4 (100%). Teratomas were positive for serum AFP (17%), and serum HCG (22%), with IHC positive for AFP (36%), CEA (81%), and cytokeratins (100%). Choriocarcinoma was positive for serum HCG (80%) and CSF HCG (100%), with IHC positive for HCG (100%), PLAP (50%), CEA (75%), HPL (50%), and cytokeratins (100%).

Conclusion: Although germinomas, yolk sac tumors, teratomas, embryonal carcinomas, and choriocarcinomas all fall under the GCT family of neoplasms, each has a distinct profile with different therapeutic guidelines and treatment challenges. Accurate diagnosis of intracranial GCT subtype is thus crucial to tailor treatment for optimal effects. Although each subtype is defined by its histological characteristics, assessment of tumor markers may enhance the diagnostic process.

Learning Objectives: By the conclusion of this session, participants should be able to (1) identify the various subtypes of GCTs, (2) understand that each subtype displays a unique pattern of molecular markers, and (3) recognize that these markers may aid in diagnosis and thus assist in dictating appropriate therapeutic measures.

Improvement in Patient Care: Our findings may help to provide noninvasive or minimally invasive means for diagnosing intracranial GCTs to efficiently and effectively determine the most appropriate therapeutic strategies to optimize patient management.