Cytogenetic analysis of skull base tumors: where do we stand?

Purpose of review This study reviewed the value of cytogenetic information for the diagnosis and assessment of prognosis in patients with skull base tumors. Recent findings Chromosomal aberrations can be tumor-specific or nonspecific, and may often show complex karyotypes with numerous chromosomal deletions and gains. These changes may derive from a step-wise genetic transformation commonly seen in these tumors. Most chromosomal abnormalities of skull base carcinomas involve several clones with complex karyotypes. Chromosomal aberrations found in squamous cell carcinoma and salivary gland carcinomas of the skull base involve similar breakpoints to those found in the carcinomas of the oral cavity, larynx, hypopharynx and nasopharynx. Complex karyotype is the hallmark of chordoma, esthesioneuroblastoma and embryonal rhabdomyosarcoma of the cranial base. In contrast, specific chromosomal translocations are characteristic for Ewing's sarcoma (11; 22) and synovial sarcoma (X; 18) of the skull base. Olfactory groove meningioma is characterized by breakpoint of chromosome arm 22q11. Summary The emergent cytogenetic data established the development of diagnostic tests utilizing molecular approaches and allowed the development of various grading systems for assessing the diagnosis and prognosis of patients with cancer.