Molecular cytogenetic analysis of archival uveal melanoma with known clinical outcome
Uveal melanoma (UM) is the most common primary intraocular tumor in the Western world. Cytogenetically, this tumor is characterized by typical chromosomal aberrations such as loss of 1p, 3, and 6q, and gain of 6p and 8q. Routinely, karyotyping and fluorescent in situ hybridization (FISH) on fresh tumor-biopsies are used to identify chromosomal changes. In addition, archival UM samples can be examined using comparative genomic hybridization (CGH). In the presented study, we used CGH on a series of 46 archival uveal melanomas to identify chromosomal changes. In 44 tumors aberrations were present and classic prognostic markers as loss of 1p (12 tumors, 26.1 %), monosomy 3 (26 tumors, 56.5%), loss of 6q (10 tumors, 21.7%), and gain of chromosome arm 8q (27 tumors, 58.7%) were observed. Gain of chromosome arms 18q or 21q was found in three UMs. Multiplex ligation-dependent probe amplification (MLPA), a novel technique in UM, was performed to verify this low number of chromosome 18 and 21 abnormalities, but we could not confirm the previously reported gain of 18q11.2 and 21q11.2 as poor prognostic factors in UM.