Ciliary body melanoma with partial deletion of chromosome 3 detected with multiplex ligation-dependent probe amplification

Abstract

The management of a patient with a small, pigmented ciliary body tumour is controversial, the various options including observation, radiotherapy, fine needle aspiration biopsy and excision biopsy. We report a case of ciliary body melanoma with partial deletion of chromosome 3, which was missed with fluorescence in situ hybridization (FISH) but detected with multiplex ligation-dependent probe amplification (MLPA). A 23-year-old woman underwent an excision biopsy for a 4.5 mm by 3.9 mm by 2.0 mm ciliary body tumour, which was assessed by histology, immunohistochemistry, FISH and MLPA. Histology showed the tumour to a melanoma of mixed cell type. FISH with a centromeric probe indicated that the tumour was of disomy 3 type with a good prognosis; however, MLPA revealed a partial deletion of the long arm of chromosome 3. This case highlights the limitations of FISH, and demonstrates the value of MLPA in testing multiple chromosomal loci of prognostic significance. To our knowledge this is the first reported case of ciliary body melanoma assessed by MLPA.