Uveal Melanoma, Chromosome 3 Monosomy, FISH, Tissue
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Uveal melanoma is the most common type of primary intraocular malignancy in adults, with an annual incidence of 6 per million. These melanomas arise within pigmented cells of the uveal tract of the eye, which consists of the choroid, ciliary body, and iris. Overall, mortality rates in patients with uveal melanoma are quite high (approximately 50%) and are due to metastatic disease. Identifying patients likely to develop metastasis is critical for establishing patient prognosis. Previous studies have demonstrated that monosomy 3 is highly correlated with the development of metastatic disease in patients with uveal melanoma.
As an aid to prognosis in patients with uveal melanoma when used in conjunction with an anatomic pathology consultation
A neoplastic clone is detected when the percent of cells with an abnormality exceeds the normal reference range for chromosome 3 probe set. A positive result is consistent with monosomy 3 and a higher risk for metastatic disease in uveal melanoma patients. A negative result suggests that aneuploidy of chromosome 3 is not present.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test is not approved by the FDA and it is best used as an adjunct to existing clinical and pathologic information.
Fixatives other than formalin (eg, Prefer, Bouin's) may not be successful for FISH assays. Although FISH testing will not be rejected due to nonformalin fixation, results may be compromised.
Paraffin-embedded tissues that have been decalcified are generally unsuccessful for FISH analysis. The pathologist reviewing the hematoxylin and eosin-stained slide may find it necessary to cancel testing.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
An interpretive report will be provided.
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. Tschentscher F, Prescher G, Horsman DE, et al: Partial deletions of the long and short arm of chromosome 3 point to two tumor suppressor genes in uveal melanoma. Cancer Res 2001 Apr 15;61(8):3439-3442
2. Prescher G, Bornfeld N, Hirche H, et al: Prognostic implications of monosomy 3 in uveal melanoma. Lancet 1996 May 4;349(9010):1222-1225
3. Cross NA, Ganesh A, Parpia M, et al: Multiple locations onchromosome 3 are the targets of specific deletions in uveal melanoma. Eye 2006 Apr;20(4):476-481
4. Parrella P, Fazio VM, Gallo AP, et al: Fine mapping of chromosome 3 in uveal melanoma: identification of a minimal region of deletion on chromosomal arm 3p25.1-p25.2. Cancer Res 2003 Dec 1;63(23):8507-8510