Test ID: TUMOR    
Chromosome Analysis, Solid Tumors

The tissue is dissociated using enzymes and/or mechanical means and transferred to culture coverslips and/or culture flasks. The cultures are incubated at 37 degrees C with 5% CO2, 5% O2, and 90% N2 for 1 to 10 days depending on cell growth. For harvesting, the cells are treated with colcemid and hypotonic solution, and fixed with glacial acetic acid and methanol. Metaphase cells are dropped onto microscope slides and are routinely stained by G- or Q-banding. Twenty metaphases are usually examined. However, if a clone is suspected, but not confirmed within 20 metaphases, 30 metaphases will be analyzed. Minimal evidence for the presence of an abnormal clone is defined as 2 or more metaphases with the same structural abnormality or chromosomal gain (trisomy), or 3 or more metaphases lacking the same chromosome. Five to 10 metaphases are captured using a computerized imaging system, and 1 or more representative karyograms from each clone are prepared to document the type of abnormality and to permit systematic interpretation of the anomalies. (De Fusco PA, Frytak S, Dahl RJ, et al: Cytogenetic studies in 11 patients with small cell carcinoma of the lung. Mayo Clin Proc 1989;64:168-176; Dewald GW, Dahl RJ, Spurbeck JL, et al: Chromosomally abnormal clones and nonrandom telomeric translocations in cardiac myxomas. Mayo Clin Proc 1987;62:558-567; Jenkins RB, Hay ID, Herath JF, et al: Frequent occurrence of cytogenetic abnormalities in sporadic nonmedullary thyroid carcinoma. Cancer 1990; 66:1213-1220; Mitelman Database of Chromosome Aberrations in Cancer [2001]. Edited by F Mitelman, B Johansson, F Mertens. Available at URL: http://cgap.nci.nih.gov/Chromosomes/Mitelman)

Samples processed Monday through Sunday. Results reported Monday through Friday, 8 a.m.-5 p.m. CST.