Test Overview

CPT Code(s)

88239, 88264, 88280, 88291

Methodology

Culture / Microscopy / Karyotype

Specimen Requirements

Container:  Sterile, leak-proof containers with transport media or sterile saline (i.e. Hanks Balanced Salt Solution). Do not place in formalin.

Optimal Quantity: 23 cm biopsy tissue

Minimum Quantity: 13 cm biopsy tissue

Storage: Room Temperature

Stability at Room Temperature: 8 hours, then refrigerate

Transportation: Avoid freezing or heating over 35OC

Turnaround Time

Final report in 10-14 days

Test Details

Clinical Significance

A chromosome analysis on solid tumor may be clinically significant to identify and diagnose acquired neoplastic conditions.  Many cytogenetic alterations have been described in some tumor types which are already known to have clinical relevance.

Clinical Background

Many lines of evidence, especially cytogenetics, strongly suggest that solid tumors arise from a common progenitor stem cell that has undergone a malignant transformation, and that subsequently continues to evolve and diverge.  The initial transformation step may result from a molecular event of mutation (deletion, insertion, translocation, base substitution, etc.).  In most solid tumors, by the time of clinical manifestation and removal or treatment of the tumor mass, significant chromosomal rearrangements and imbalances have occurred.  Even with complex karyotypes and heterogeneous tumor cell populations it has been possible to describe certain chromosomal abnormalities that are specific for certain tumor types, nonrandom changes that may be important to tumor progression, secondary changes that occur during evolution and characteristic karyotypic anomalies within given tumor tissue types that might be used to separate different clinical subgroups.  Chromosome analysis on tumors serves as a diagnostic study for relevant acquired chromosomal aberrations in one test, whereas molecular studies are significant in cases where a diagnosis has been made or a suspicion exists and specific testing is targeted.

Methods

Tumor samples are initiated and cultured using a dissociation and dispersion of cells technique.  They are harvested within 1 week of tumor cell growth and division followed by G-banding. Analysis is carried out by two certified technologists using manual metaphase scanning and karyotyping utilizing the Cytovision software.  Each technologist analyzes a minimum of 10 metaphases after which they are reviewed by the manager and reported by the director.

Interpretation of Results

The morphologic interpretation and correlation of results on all cases is performed by a board-certified doctoral level scientist (laboratory director). The final report identifies the chromosomal sex and modal chromosome number.  If abnormalities are present, they are explained in a paragraph which helps to clarify and correlate clinical findings with pathological morphology. FISH testing is recommended to support or confirm chromosome aberrations or when inconclusive results are found.  References are included in the report to help the referring physician with interpretation, which include books or journals that contain appropriate information.