NOV 06, 2007
A group of distinguished investigators has reported in Ophthalmology seven years of experience with routine cytogenetic analysis of uveal melanoma in a clinical environment. Their findings suggest that cytogenetic studies should be considered part of the histopathologic evaluation for all choroidal melanomas.
The clinical and histologic features of uveal melanomas shown to have prognostic significance include tumor size, ciliary body involvement, evidence of extraocular extension, cell type (tumors comprised of epithelioid melanoma cells having a worse prognosis), the presence of vascular closed loops or networks and mitotic activity. More recently, cytogenetic studies have been performed on tumor samples, and changes in chromosome 3 (monosomy 3) and chromosome 8 (trisomy 8 and isochromosome 8q) have been identified as potentially significant prognostic parameters.
Investigators collected data on chromosome 3 and 8, as well as disease-specific mortality, for 356 melanoma patients. Their findings demonstrate that monosomy 3, in conjunction with basal tumor diameter and tumor cell type, had prognostic significance. The value of this investigation is enhanced by the fact that the cytogenetic studies were performed as part of routine clinical practice and not under artificial research conditions.
Furthermore, ongoing studies may show whether the benefit of tumor grading is great enough to justify the risk of a diagnostic biopsy (e.g. fine-needle aspiration biopsy) in patients with choroidal melanoma.